Answer:
Your score is -9.
Step-by-step explanation:
A chemist wants to make 54 ml of 18% acid solution by mixing 11% acid solution and a 20% acid solution how many ml should the chemist use
The chemist must use 12 ml of the 11% acid solution and 42 ml of the 20% acid solution to make a solution of quantity 54 ml of 18% concentration acid solution.
It is already given that the chemist wishes to make a solution of 54 milliliters of 18 percent concentration using two different solutions of concentration 11% and 20% each.
Now let us consider that the quantity of acid to be present in the final solution is (18/100)×54 = 9.72 ml
If we consider that x ml of 11% solution and y ml of 20% solution are added, then following relations can be obtained:
Total volume of x and y in the final solution = x + y = 54 ...(1)
Considering the concentration of acid and its volume, the following equation is formed:
0.11x + 0.2y = 9.72 ...(2)
Solving the equations (1) and (2) for the value of x and y, we get:
x = 54 - y
∴ 0.11(54 - y) + 0.2y = 9.72
⇒ 5.94 - 0.11y + 0.2y = 9.72
⇒ 0.09y = 3.78
⇒ y = 42 ml
Putting the value of y in equation (1), we get
x = 54 - y
x = 54 - 42 = 12 ml
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Suppose that researcher; using data on class size (CS) and average test scores (S) from 100 third-grade classes, estimates the OLS regression: S = 520. 4 5. 82 CS, (20. 4) (2. 21) Rz = 0. 08, SER = 11. 5 a) A classroom has 22 students What is the regression prediction for that classroom average test score?b) Last year classroom had 19 students and this year it has 23 students What is the regression's prediction for the change in the classroom average test score? c) The sample average class size across 100 classrooms is 21. 4. What is the sample average ofthe test scores across the 100 classrooms? d) Interpret the R? measure. Is it large Or small? What does it mean? e) What is the magnitude of the coefficient of correlation in this model? Interpret the R? measure the context of the correlation coefficient: What is the difference in the interpretation of the twO measures of the linear association of the tWo random variables? f) What is the sample standard deviation of test scores across the 100 classrooms? Hint: Use the formula for the standard error of the regression (SER) to get the sum of squared residuals:
a) The regression prediction for a classroom with 22 students is 651.24.
b) The predicted change in the classroom's average test score for a change from 19 to 23 students is 23.28.
c) The sample average of the test scores across the 100 classrooms is approximately 639.88.
d) The R-squared (R²) measure is 0.08, which indicates a relatively small amount of variation in test scores is explained by variation in class size.
e) The magnitude of the coefficient of correlation (r) is 0.283, indicating a weak positive linear association between class size and test scores.
f) The sample standard deviation of test scores across the 100 classrooms is approximately 11.28.
a) If a classroom has 22 students, then the regression prediction for that classroom's average test score would be:
S = 520.4 + 5.82(22) = 651.24
b) If last year a classroom had 19 students and this year it has 23 students, then the predicted change in the classroom's average test score would be:
ΔS = 5.82(23-19) = 23.28
Note that this calculation assumes that the other factors affecting test scores remain the same, which may not be realistic.
c) The sample average class size across 100 classrooms is 21.4. To find the sample average of the test scores across the 100 classrooms, we simply plug in the average class size into the regression equation:
S = 520.4 + 5.82(21.4) = 639.88
Therefore, the sample average of the test scores across the 100 classrooms is approximately 639.88.
d) The R-squared (R²) measure in this model is 0.08. This is a relatively small value, which means that only 8% of the variation in test scores can be explained by variation in class size. The remaining 92% of the variation is due to other factors that are not captured by the regression model.
e) The magnitude of the coefficient of correlation (r) in this model can be found by taking the square root of R²:
r = √0.08 = 0.283
The interpretation of r is that there is a weak positive linear association between class size and test scores. This means that as class size increases, test scores tend to increase slightly, but the relationship is not very strong.
The difference between R² and r is that R² measures the proportion of variance in the dependent variable (test scores) that is explained by the independent variable (class size) and any other variables in the model, while r measures the strength and direction of the linear association between the two variables.
f) The standard error of the regression (SER) is given as 11.5. This represents the average amount of variation in test scores that is not explained by the regression model. The sample standard deviation of test scores can be estimated by multiplying SER by the square root of (1 - R²) and dividing by the square root of the number of observations:
s = SER × √(1 - R²) / √n
= 11.5 × √(1 - 0.08) / √100
= 11.28
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what is 11.5 + 10.5 in math
Answer:
22
Step-by-step explanation:
10+11=21
.05+.05=1
1+21=22
PLEASE HELP ME IM TIMED
Answer:
12
Step-by-step explanation:
g(-4)=2(-4)^2+4(-4)-8
g(-4)=8
f(8)=2(8)-4
f(8)=12
Question
What is the expanded form of this number?
204.017
⁰ (2 x 100) + (4 x 1) + (1 x 1/10) + (7 x 1/1000)
⁰ (2 x 100) + (4 x 1) + (1 x 1/100) + (7 x 1/1000)
⁰ (2 x 100) + (4 x 1) + (1 x 1/10) + (7 x 1/100)
⁰ (2 x 100) + (4 x 1) + (1 x 1/100) + (7 x 1/100)
Answer:
B
Step-by-step explanation:
2 is hundred = 2x100
0 is tens =0x10
4 is unit =4 x 1
All numbers after the decimal point to the right are fractions
0 is tenth = 0/10 =0
1 is hundredth =1/100
7 is thousandth 7/1000
Now you can choose the right answer
A construction crew is lengthening a road that originally measured 51 miles. The crew is adding one mile to the road each day. The length, L (in miles), after d days of construction is given by the following.
L= 51+d
What is the length of the road after 38 days?
Answer: 89 miles
Step-by-step explanation:
Well, if the construction crew added one mile every day for 38 days, then the formula would look like this.
L = 51 + (38)
51 + 38 = 89
L = 89 miles
Solving a rational equatic Solve for v. (3)/(4v)+(7)/(v)=1 If there is more than one solution, If there is no solution, click on "No s
There is only one solution for this equation. v = 31/4 is the only solution to this equation.
To solve for v in the equation (3)/(4v)+(7)/(v)=1, we need to get a common denominator and then solve for v.
Step 1: Get a common denominator. The common denominator for 4v and v is 4v. So, we will multiply the second fraction by 4/4 to get a common denominator:
(3)/(4v)+(7*4)/(v*4)=1
Step 2: Simplify the fractions:
(3)/(4v)+(28)/(4v)=1
Step 3: Combine the fractions:
(3+28)/(4v)=1
Step 4: Simplify the numerator:
(31)/(4v)=1
Step 5: Cross-multiply to solve for v:
31=4v
Step 6: Divide both sides by 4 to get v:
v=31/4
The solution is v=31/4.
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iven the polynomial 4x^(2)y^(4) - 9x^(2)y^(6), rewrite as a product of polynomials
The polynomial 4x^(2)y^(4) - 9x^(2)y^(6) can be rewritten as a product of polynomials as:
x^(2)y^(4)(2y + 3)(2y - 3)
The polynomial 4x^(2)y^(4) - 9x^(2)y^(6) can be rewritten as a product of polynomials by factoring out the common factor of x^(2)y^(4). This leaves us with:
x^(2)y^(4)(4 - 9y^(2))
Now, we can factor the polynomial inside the parentheses as a difference of squares:
x^(2)y^(4)(2y + 3)(2y - 3)
Therefore, the polynomial 4x^(2)y^(4) - 9x^(2)y^(6) can be rewritten as a product of polynomials as:
x^(2)y^(4)(2y + 3)(2y - 3)
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1. he marks of Calculus I in the final examination in a private college are normally distributed with a mean of 45 marks and a standard deviation of 10 marks. (a) If a student is chosen at random, find the probability that his/her mark is less than 52. 0.75$ (b) If the college has 220 students who sat for the examination, find the number of students whose marks are between 45 and 55. 75 (c) Find the percentage of students whose marks exceed 40. 69.15%
2. A survey on the study habits of 1000 HSM students shows that 550 use reference books, 750 have regular study times and all those who use reference books have regular study time. A HSM student is chosen at random; what is the probability that the student
a) only has regular study time?
b) either has a regular study time or uses
reference books?
c) neither studies regularly nor uses reference
books?
1. (a) Using a z-table, we can find the probability corresponding to this z-score, which is 0.758. Therefore, the probability that a student's mark is less than 52 is 0.758. (b) To find the number of students whose marks are between 45 and 55, we need to calculate the z-scores for 45 and 55 . The z-score for 45 is (45 - 45) / 10 = 0, and the z-score for 55 is (55 - 45) / 10 = 1. (c) The probability corresponding to this z-score is 0.3085. Therefore, the percentage of students whose marks exceed 40 is 1 - 0.3085 = 0.6915, or 69.15%. 2. (a) So, the probability that a student only has regular study time is 750/1000 - 550/1000 = 200/1000 = 0.2. (b) The probability that a student either has a regular study time or uses reference books is 750/1000 + 550/1000 - 550/1000 = 750/1000 = 0.75. (c) The probability that a student neither studies regularly nor uses reference books is 1 - 0.75 = 0.25.
Therefore, the probability that a student's mark is between 45 and 55 is 0.8413 - 0.3413 = 0.5. Since there are 220 students in the college, the number of students whose marks are between 45 and 55 is 0.5 * 220 = 110.
To find the probability that a student's mark is less than 52, we need to calculate the z-score for 52 using the formula z = (x - μ) / σ, where x is the value we are interested in, μ is the mean, and σ is the standard deviation. So, z = (52 - 45) / 10 = 0.7.
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Damion is building a pool in his backyard. He needs the pool to have a length of 12.5 meters (m) and a width of 5.7 m. He also needs the volume of the
pool not to exceed 114 cubic meters (m³).
12.5 m
The Height of the pool should be 1.6 m.
What is Volume?Every three-dimensional item requires some amount of space. The volume of this space is measured. Volume is defined as the space occupied by an object inside the confines of three-dimensional space. It is also known as the object's capacity.
Given:
length of pool= 12.5 m
width of pool = 5.7 m
and, Maximum volume of pool = 114 m³
So, Volume= l w h
114 = 12.5 x 5.7 x h
114 = 71.25 h
h = 114/ 71.25
h = 1.6 m
Thus, the height can be 1.6 m.
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if you have any more questions let me know i need help
Answer:
x=6
My best attempt
Step-by-step explanation:
The ratio is 4:5.6 from top to bottom.
We have a ratio of x:8.4
We will make an equation.
4:5.6=x:8.4
Cross multiply:
5.6x=4x8.4
5.6x=33.6
Divide both sides by 5.6:
x=6
If the figures below are similar, find the scale factor of Figure B to Figure A.
A. 3/16
B. 20/3
C. 16/3
D. 3
E. 3/20
F. 1/3
565 545 245 450 350How much money will they save monthly by the move to Oakland?
Benito and his family will save $1,315 by the move to Oakland.
Savings in house = $1200 - $565
= $635
Savings in food = $655 - $545
= $110
Saving in health care = $495 - $245
= $250
Saving in taxes = $625 - $450
= $175
Saving in necessities = $495 - $350
= $145
Total saving = $635 + $110 + $250 + $175 + $145
= $1,315.
Hence, Benito and his family will save $1,315 by the move to Oakland.
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Your question is incomplete, the complete question is:
Benito's family is thinking of relocating from Los Angeles to Oakland to save money. They set up a budget comparing the cost of living for both cities.
Oakland Los Angeles
Cost Housing $565 $1200
Food $545 $655
Health Care $245 $495
Taxes $450 $625
Other Necessities $350 $495
How much money will they save monthly by the move to Oakland? $1315, $1560, $1665, or $1765?
A washing machine holds 10 gallons of water and drains 8 of the gallons in 2 minutes. What was the average flow through the pipe in 2 minutes?
gallons/min
a printer makes more than three copies of labels every hour graph the number of books made in 2 hours.
Wyatt plays a vides game called Rock Climber. He starts with 100 points. He loses 7 points each time he falls off a rock. Wyatt has fallen off 6 rocks. How many points does he have left? points Submit
The number of points Wyatt has left is 58.
If Wyatt loses 7 points every time he falls off a rock and he falls off 6 rocks, he will lose a total of 42 points (7 x 6 = 42). To find out how many points he has left, we can subtract 42 from his starting points of 100:
100 - 42 = 58
Therefore, Wyatt has 58 points left after falling off 6 rocks in the Rock Climber video game.
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degree 4 polynomial with zeroes 4 and -(6)/(5) (each with multiplicity 1) and 0 (with multiplicity 2)
The degree 4 polynomial with the given zeroes is P(x) = x^4-(94/5)x^3-(24/5)x^2.
A degree 4 polynomial with the given zeroes can be represented as:
P(x) = (x-4)(x+(6)/(5))(x-0)^2
Simplifying the polynomial gives:
P(x) = (x-4)(x+(6)/(5))(x^2)
P(x) = (5x-20)(x+(6)/(5))(x^2)
P(x) = (5x^2-20x+(6x)/(5)-24/(5))(x^2)
P(x) = (25x^2-100x+6x-24)/(5)(x^2)
P(x) = (25x^2-94x-24)/(5)(x^2)
P(x) = (5x^4-94x^3-24x^2)/(5)
P(x) = x^4-(94/5)x^3-(24/5)x^2
So the degree 4 polynomial with the given zeroes is P(x) = x^4-(94/5)x^3-(24/5)x^2.
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Use simple interest to find the ending balance.
$7,900 at 1.9% for 2 & 3/4 years
Answer:
To calculate the ending balance, we can use the following formula:
Ending Balance = Principal x (1 + Interest Rate x Time)
Given:
Principal = $7,900
Interest Rate = 1.9%
Time = 2 3/4 years
Therefore,
Ending Balance = $7,900 x (1 + 0.019 x 2.75) = $8,084.60
Answer: 8319.66994
Step-by-step explanation:
your initial x your interest all raised to your time interval.
7,900(1+.019)^2.75
A young group and their leaders visited mammoth cave. two adults and five students in one been paid $77 for the hand avenue tour of the cave. Two adults and seven segments
students in the second van pair $95 for the same tour. Find the adults price and the student pieces
price of the tour.
The price for adults to visit the mammoth cave is $16 and the price for students is $9.
What is the adult and students price?The first step is to form a system of equations that represent the information in the question.
2a + 5s = 77 equation 1
2a + 7s = 95 equation 2
Where:
a = price of one adult
s = price of one student
The elimination method would be used to solve the equations.
Subtract equation 1 from equation 2:
2s = 18
Divide both sides of the equation by 2
s = 18/2
s = $9
Substitute for s in equation 1:
2a + 5(9) = 77
2a + 45 = 77
2a = 77 - 45
2a = 32
a = 32 / 2
a = 16
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I paid $9.54 for 1.2 pounds of fresh fish.
How much did the fresh fish cost per pound?
Use interval notation to write the intervals over which f is a) increasing, b)
decreasing, and c) constant.
-5-4-3-2-1
S
f
3+
CN
1+
-1-
-2+
-3+
-4-
-5+
1 2 3 4 5 X
Answer: (a) From the graph, we can see that the function f is increasing on the interval [-5, -1), (-2, 2), and (3, 5]. Therefore, we can write the increasing intervals in interval notation as:
[-5, -1) ∪ (-2, 2) ∪ (3, 5]
(b) From the graph, we can see that the function f is decreasing on the interval (-1, 1) and (2, 3]. Therefore, we can write the decreasing intervals in interval notation as:
(-1, 1) ∪ (2, 3]
(c) From the graph, we can see that the function f is constant on the interval [-4, -3]. Therefore, we can write the constant interval in interval notation as:
[-4, -3]
Step-by-step explanation:
Hi, Could you please show and explain the methods for
calculating Mean, Median and Mode?
Mean: The mean is the average of a set of numbers. To calculate the mean, you add up all the numbers in the set and then divide by the total number of numbers in the set.
Median: The median is the middle number in a set of numbers when they are arranged in ascending or descending order.
Mode: The mode is the number that appears most frequently in a set of numbers.
Hi there! Yes, I can certainly show and explain the methods for calculating Mean, Median, and Mode. These are all measures of central tendency, which are used to describe the center of a data set.
Mean: The mean is the average of a set of numbers. To calculate the mean, you add up all the numbers in the set and then divide by the total number of numbers in the set. For example, if you have the numbers 2, 4, 6, 8, and 10, the mean would be (2 + 4 + 6 + 8 + 10) / 5 = 6.
Median: The median is the middle number in a set of numbers when they are arranged in ascending or descending order. If there is an odd number of numbers in the set, the median is the middle number. If there is an even number of numbers in the set, the median is the average of the two middle numbers. For example, if you have the numbers 2, 4, 6, 8, and 10, the median would be 6. If you have the numbers 2, 4, 6, 8, 10, and 12, the median would be (4 + 6) / 2 = 5.
Mode: The mode is the number that appears most frequently in a set of numbers. If there is more than one number that appears the same number of times, there can be more than one mode. For example, if you have the numbers 2, 4, 6, 8, 10, and 10, the mode would be 10 because it appears twice and the other numbers only appear once.
I hope this helps! Let me know if you have any other questions.
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Determine if the given function is linear, quadratic, or exponential.
f(x) = 5 (2.3)^x
The given function f(x) = 5 (2.3)^x is an exponential function.
The given function is f(x) = 5 (2.3)^x.
To determine if the function is linear, quadratic, or exponential, we need to examine the form of the function.
A linear function has the form f(x) = mx + b, where m is the slope and b is the y-intercept.
A quadratic function has the form f(x) = ax^2 + bx + c, where a, b, and c are constants.
An exponential function has the form f(x) = ab^x, where a and b are constants.
The given function, f(x) = 5 (2.3)^x, is in the form of an exponential function, with a = 5 and b = 2.3. Therefore, the function is exponential.
In conclusion, the given function f(x) = 5 (2.3)^x is an exponential function.
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One lap of a race track is 1 km.
Work out the total distance, in kilometres (km), of 2 laps of the race
track.
Give your answer as an integer or as a mixed number in its simplest form.
The total distance of 2 and 1/7 laps of the race track is given as follows:
[tex]3\frac{39}{42}[/tex]
How to obtain the total distance?The total distance is obtained applying the proportions in the context of the problem.
The length of one lap, as a fraction, is given as follows:
1 and 5/6 km = (6 + 5)/6 = 11/6 km.
The number of laps is given as follows:
2 and (1/7) = (14 + 1)/7 = 15/7 laps.
Hence the total distance is given as follows:
11/6 x 15/7 = 165/42.
165 divided by 42 has a quotient of 3 with a remainder of 39, hence the mixed number representing the number of laps is given as follows:
[tex]3\frac{39}{42}[/tex]
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Landon has a jar of coins. He chooses a coin at random, notes what type of coin it is, and returns it to the jar. After 12 trials, he calculates the experimental probabilities shown in the table.
On the 13th trial, Landon chooses a nickel.
What is the experimental probability of choosing a nickel based on the 13 trials?
Coin
Penny
Nickel
Dime
Quarter
Experimental
Probability
1/2
1/4
1/6
1/12
The experimental probability of choosing a nickel based on the 13 trials is 4/13.
What is probability ?
Probability can be defined as ratio number of favourable outcomes, total number of outcomes.
Based on the experimental probabilities shown in the table, we can calculate the probability of choosing a nickel on the 13th trial using the following steps:
Calculate the total number of trials: 12 + 1 = 13
Calculate the total number of times a nickel was chosen in the 12 trials: 12 * 1/4 = 3
Add 1 to the total number of times a nickel was chosen to account for the 13th trial: 3 + 1 = 4
Calculate the experimental probability of choosing a nickel based on the 13 trials: 4/13
Therefore, the experimental probability of choosing a nickel based on the 13 trials is 4/13.
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A new town developed in Wyoming due to mineral activity. It began with 150 workers/managers moving in, so in year zero its population was 150, after one year, 620 people lived in the new city. After two years, 1170 people inhabited the town, and by the end of the third year, the population was 1950. Find a linear regression that fits this data and predict the towns population by year 12.( what is the r^2 value?) what is the equation of the line? the r value? and prediction of population in year 12?
The equation of the line is y = 780x + 150, r² value is 0.186, the r value is 0.431, and the predicted population in year 12 is 9450.
To find a linear regression that fits this data, we need to use the following formula:
y = mx + b
where y is the population, x is the number of years, m is the slope, and b is the y-intercept.
We can use the data given to find the slope (m) and the y-intercept (b). The slope can be found by calculating the difference in the population between two consecutive years and dividing it by the difference in the number of years. The y-intercept can be found by plugging in the values of x and y into the equation and solving for b.
Using the data given, we can find the slope and y-intercept as follows:
m = (1950 - 1170) / (3 - 2) = 780
b = 150 - (0)(780) = 150
Therefore, the equation of the line is:
y = 780x + 150
To find the r² value, we can use the formula:
r² = 1 - (SSres / SStot)
where SSres is the sum of squares of residuals and SStot is the total sum of squares.
SSres = (150 - 150)² + (620 - 930)² + (1170 - 1710)² + (1950 - 2490)² = 2,484,400
SStot = (150 - 1222.5)² + (620 - 1222.5)² + (1170 - 1222.5)² + (1950 - 1222.5)² = 3,051,875
r² = 1 - (2,484,400 / 3,051,875) = 0.186
The r value can be found by taking the square root of the r²value:
r = √0.186 = 0.431
To predict the population in year 12, we can plug in the value of x into the equation of the line:
y = 780(12) + 150 = 9450
Therefore, the predicted population in year 12 is 9450.
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What does it equal?
-8=z/14
If you are solving for z:
-8=z/14
multiply by 14 on both sides:
z = -112
Which equation can be used to find the area of the figure below?
F.A = (10⋅82
)+
(16⋅8
)
G.A = (6⋅82
)+
(10⋅8
)
H.A = (6⋅82
)+
(6⋅8
)
J.A = (6⋅8
)+
(10⋅8
)
The equation that can be used to find the area of the figure below is: (10)(8) + (1/2)(6)(8).
What is area of composite figure?The area of mixed shapes is the area that is covered by any hybrid shape. The composite shape is a shape created by joining a small number of polygons to create the desired shape. These forms or figures can be constructed from a variety of shapes, including triangles, squares, quadrilaterals, etc. To calculate the area of a composite object, divide it into simple shapes such a square, triangle, rectangle, or hexagon.
A composite form is essentially a combination of fundamental shapes. A "composite" or "complex" shape is another name for it.
The area of the rectangle is given as:
A = (l)(w)
A = 10(8)
A = 80 sq. units
The area of the triangle is:
A = 1/2(b)(h)
In the figure:
b = 16 - 10 = 6 and h = 8.
A = 1/2(6)(8)
A = 24 sq. units
The total area of the figure is:
Area = area of rectangle + area of triangle
Area = 80 + 24
Area = 104 sq. units
Hence, the equation that can be used to find the area of the figure below is: (10)(8) + (1/2)(6)(8).
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If 1/6 of a gallon of milk is shared equally between three friends how much milk will each friend get
the friends receive one eighteenth each
Find the values of a and b to express this recurring decimal as a fraction.
Simplify this fraction as much as possible before entering your answer.
0.727272... = [tex]\frac{a}{b}[/tex]
a=
b=
Answer: Let x = 0.727272...
Then, 100x = 72.727272...
Subtracting x from 100x gives:
100x - x = 72.727272... - 0.727272...
99x = 72
x = 72/99
We can simplify this fraction by dividing both the numerator and denominator by their greatest common factor, which is 9. Therefore:
x = (72/9) / (99/9) = 8/11
So, a = 8 and b = 11. Therefore, the recurring decimal 0.727272... can be expressed as the fraction 8/11.
Step-by-step explanation: