The pH of a solution is measured eight times by one operator using the same instrument. She obtains the following data: 7.15, 7.20, 7.18, 7.19, 7.21, 7.20, 7.17, and 7.18. (a) Calculate the sample mean. Round your answer to 3 decimal places. (b) Calculate the sample variance. Round your answer to 6 decimal places. (c) Calculate the sample standard deviation. Round your answer to 3 decimal places. (d) Which of the following are potential major sources of variability in the experiment

Answers

Answer 1

Answer:

(a)7.185

(b)0.000371

(c) 0.019

(d)Sample variance and Sample standard deviation

Step-by-step explanation:

We are given the following sample data.

7.15, 7.20, 7.18, 7.19, 7.21, 7.20, 7.17, 7.18.

(a) Calculate the sample mean. Round your answer to 3 decimal places.

The formula for sample mean =

Sum of terms/Number of terms

= 7.15 + 7.20+ 7.18+7.19+7.21+7.20+7.17+ 7.18/8

= 57.48/8

= 7.185

(b) Calculate the sample variance. Round your answer to 6 decimal places.

The formula for sample Variance =

(x - mean)²/n - 1

n = 8

Sample variance = (7.15 - 7.185)² + (7.20-

7.185)²+ (7.18 -7.185)² + (7.19 -7.185)² + (7.21 - 7.185)² + (7.20 - 7.185)² + (7.17 - 7.185)² + (7.18 - 7.185)² /8 - 1

= 0.001225 + 0.000225+ 0.000025+ 0.000025 + 0.000625 + 0.000225 + 0.000225 + 0.000025/7

= 0.0026/7

= 0.000371428571

Approximately to 6 decimal places = 0.000371

(c) Calculate the sample standard deviation. Round your answer to 3 decimal places.

The formula for Sample Standard Deviation = √Sample variance

= √0.000371428571

= 0.01927248223

To 3 decimal places = 0.019

(d) Which of the following are potential major sources of variability in the experiment

Sample variance

Sample standard deviation


Related Questions

which number line model represents the expression -2+ (- 7/2)

Answers

Answer: -5.5

Step-by-step explanation:

(; -2= 7/2

-5+ 7 =12

12/2=5

HELP ANSWER AS FAST AS U CAN
Acceptance into an acting workshop is highly competitive. Last year only 2 out of every 15 applicants were accepted into the workshop. This year the work shop accepted 40 out of 600 possible applicants.

Compare this years acceptance rates to that of last years rate. Is this years acceptable rate higher or lower or equal to last year’s acceptance rate? Explain your reasoning.

Answers

Answer:

is this a test

Step-by-step explanation:

kshsjwoo2o1k1 snsn

which fraction is equivalent to 0.36

Answers

Answer: 9/25, Percentage: 36%

Find the total mass of the triangular region shown below. All lengths are in cm, and the density of the region is sigma(x) = 1 + x grams/cm^2

Answers

Answer:

3 grams

Step-by-step explanation:

We are going to take the mass of a bunch of little strips below the triangle "roof." To do this, we must figure out what formula for the mass we'll use, in this case, we'll use:

Mass of strip = denisty * area = (1+x)*y*deltax grams

now, because the "roof" of the triangle contains two different integrals (it completely changes direction), we will use TWO integrals!

**pretend ∈ is the sum symbol

Mass of left part = lim x->0 ∈ (1+x)*y*deltax = inegral -1 to 0 of (1+x)*3*(x+1) = 3 * integral -1 to 0 of (x^2 + 2x + 1) = 3 *  1/3 = 1

Mass of left part = lim x->0 ∈ (1+x)*y*deltax = inegral 0 to 1 of (1+x)*3*(-x+1) = 3 * integral 0 to 1 of (-x^2 + 1) = 3 * 2/3 = 2

Total mass = mass left + mass right = 1 + 2 = 3 grams

1.) A pipe bursts in your house and you call 2 plumbers for estimates. Plumber A says he
charges $40 to check the problem and $ 55 an hour to repair. Plumber B says he
charges $ 60 to check the problem and $ 40 an hour. If the repair takes 4 hours to
complete, which plumber would be a better option.

Answers

Answer: Plumber B

Step-by-step explanation:

Plumber A: First, multiply $55 times 4, then add the fee of $40. This will give you $260 as total. This is how much it would cost for Plumber A.

Plumber B: Multiply $40 by 4 and then add $60. This gives you $220, showing that Plumber B is a better option.

Answer:

Plumber B

Step-by-step explanation:

We could set up 2 expressions, and set the time to be 4 hours, and see which plumber costs less:

Plumber A: 40+55*4 = $260

Plumber B: 60+40*4 = $220

Plumber B is cheaper, so therefore he/she is the better option.

QUADRATIC EQUATION – WORD PROBLEMS
The length of a playground is 15 meters more than the width and the area is 2700 . If the width is x m, find an equation in x and hence, find the dimensions of the classroom.

The answer width =45 m , length = 60 m
I just need the steps

Answers

Answer:

let the width of the playground be X

length will be (X+15)

area - length * width = 2700

(X+15)* X = 2700

x^2+15x-2700=0

x^2+60x-45x-2700=0

X(X+60)-45(X+60)=0

(X+60)(x-45)=0

x=45 because, the dimensions cannot be in negative

so length = 60 and width = 45

The table represents a linear function.
What is the slope of the function?
-10
-5
5
10

Answers

using two points to find the slope use
y2-y1/x2-x1
i chose points (0,4) and (2,14)
14-4/2-0
10/2
5
The slope is 5

You have discovered another alien.
What is the equation of the line that provides the
correct path to rescue this alien?
y = 5
y = x + 5
y = -x + 5
y = 5x

Answers

Answer is : y= -x + 5

Answer:

y=-x+5

Step-by-step explanation:

have a great day :))))

If line n bisects segment CE, find the positive value of x.

A.6
B.10
C.15
D.9

Answers

9514 1404 393

Answer:

  D.  9

Step-by-step explanation:

The segment lengths are equal, so ...

  x^2 = 90-x

  x^2 +x -90 = 0 . . . . . . add x-90 to put in standard form

  (x +10)(x -9) = 0 . . . . . factor

The solutions are the values of x that make the factors zero: -10, 9.

The positive value of x is 9.

How many 1/8 teaspoons are equal to 4 3/4 teaspoons?

Answers

1. Convert fraction into same decimal.

To find this answer, we want to first convert the fraction so that the denominators are the same:

3/4 = ?/8

Divide the original denominator by the needed-to-be denominator.

8 / 4 = 2

Do reversal calculations

4 x 2 = 8

So, now that we know to multiply the original denominator by 2 to get the new denominator, multiple the numeriator by the same.

3           6

_  x 2 = _

4           8

So now, the new equation is:

How many 1/8 teaspoons are equal to 4 6/8 teaspoons.

(The reason why you must convert is because then you can simply say that the fraction is 6 1/8's, which means you just have to worry about the whole numbers.

2. Convert the whole numbers into a fraction to make it easier.

In order to convert whole numbers into fractions, first find the denominator your using. Which in this case, it is 8.

?/8

Now remember, for it to be a whole number, the numeriator and denominator MUST be the same.

8/8 = 1

Now remember, there are four 1's. Multiply the numeriator by 4, but keep the denominator the same or else the equation is ruined.

32/8 = 4

3. Add all your information together.

DO NOT forget to add the information you collected during the equation, or else you will get a wrong answer. Add the equation's final answer to the whole numbers final answer.

32 / 8 + 6 / 8 = ?

32 / 8 + 6 / 8 = 38 / 8

Well now, remember something. It is asking us, how many 1/8's were in the equation 4 3/4. We have transformed 4 3/4 into a whole equation, 38/8.

Now, all you need to do is look at the numeriator.

What number do you see?

You see 38.

The denominator is the correct denominator that you need. So, the number of the numeriator is the answer to the equation.

So, how many 1/8 are in 38/8?

38!

The number of ⅛ teaspoons will equal 4¾ teaspoons is; 38 teaspoons

We want to find how many ⅛ teaspoons will equal 4¾ teaspoons.

To start with, let us convert 4¾ teaspoons from mixed fraction to improper fraction to get;

4¾ teaspoons = 19/4 teaspoons

Now to find out how many ⅛ teaspoons will equal 19/4 teaspoons, all we need to do is to divide 19/4 by ⅛

Thus;

19/4 ÷ 1/8

>> 19/4 × 8/1

>> 38 teaspoons

In conclusion the number of ⅛ teaspoons that are equal to 4¾ teaspoons is 38 teaspoons.

Read more about division of fractions at; https://brainly.com/question/1622425

evaluate the expression if m = -5 and n = 7
|-m+n|
|m+n|
-|m+(-n)|
-|-m|+n

Answers

Answer:

n  m

Step-by-step explanation:

mn

8. The area of a square weightlifting platform is 16 m2. a) Sketch the platform. What are its dimensions? b) What is the perimeter of the platform?

Answers

Answer:

Step-by-step explanation:

Area of a square platform = Length × Length

A = L² (note that all the sides of a square are equal)

Given

A = 16m²

L² = 16

L = √16

L = 4m

Hence the dimension of the square is 4m by 4m (use the dimension when sketching the diagram. Al the sides is the diagram must be the same i.e 4m)

Perimeter of the square = 4L

P = 4(4)

P = 16m

Hence the perimeter of the platform is 16m

Mason sells life insurance policies. He earns a 12 percent commission on every policy he sells. He made the following sales this week: Monday $425.00, Tuesday $694.25, Wednesday $296.14, Thursday $501.85, and Friday $358.76. What is his commission for the week?

Answers

Answer: Mason made $185.00

Step-by-step explanation:

For the first 10 suits he made $12.50 each suit, then he made $20 for the additional 3.  (Just ignore the "suits part ._.)

250*.05=12.50

250*.08=20

12.50*10=125

3*20=60

125+60=185.

help help pls plz pls fast pls

Answers

Answer:

The third one

Step-by-step explanation:

Answer:

Hey mate......

Step-by-step explanation:

The third option is the correct one....

hope it helps,

mark me as the brainliest.....

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18 pounds for 9 dollars what is it in unit rate

Answers

Answer:

0.5

Step-by-step explanation:

9 dollars divided by 18lbs.

9/18 = 0.5

$0.50/lbs

A food bank sends a truck with 400 pounds of food pantries every week, and receives a government surplus shipment of 3,200 pounds every other week. If it has 10,000 pounds of food on hand at the beginning of July, how much will it have six weeks later?

Answers

I’m pretty sure the answer would be 22,000 considering that have 10,000 pounds of food on hand, and every other week they receive 3,200 pounds of more food so that would be 3x 3,200= 9,600 because that is half of 6 weeks and every week of six weeks they receive 400 pounds of more food so 6x400 = 2,400
9,600+2,400=12,000 + 10,000 =22,000 pounds of food.

What’s the value of x ?

Answers

Answer:

6

Step-by-step explanation:

x = 6

12x + 3 = 11x + 9

112x - 11x = 9 -3

x = 6

1 inch= 2.54 cm
How many centimeters equal 8 feet?
20.32 cm
96 cm
30.48 cm
243.84 cm

Answers

20.32. Is the answer
243.84

Since 8 feet is 96 inches, 96 * 2.54 = 243.84

By using the 20 percent off coupon that she found in the newspaper, Jill saved $4 on the extra large bag of dog food that she bought.

Percents
Total
20%
20%
20%
20%
20%
100%
$4
$4
$4
$4
$4


What was the cost of the bag of dog food without the coupon?
$8
$12
$16
$20

Answers

The correct answer for this would be $20

Answer: The answer would be $20, because 20% 5 times is 100% and 4 times 5 is 20

What is the value of 2 5/8 divided by 7/10

Answers

Answer:

3  3/4

(Decimal: 3.75)

Step-by-step explanation:

DUE TODAY PLEASE HELP​

Answers

Answer: 6. 113.398  7.  354.882  8. 4.82803

HOPE THIS HELPS!

Step-by-step explanation:

slove for x 3x-24=81​

Answers

Answer:

15

Step-by-step explanation:

Answer:

x = 35

Step-by-step explanation:

[tex]3x-24=81[/tex]

Collect like terms and simplify

[tex]3x=81+24\\\\3x = 105[/tex]

Divide both sides of the equation by 3

[tex]\frac{3x}{3} = \frac{105}{3} \\\\Simplify\\\\x = 35[/tex]

15 points

Draw a square



side 5cm
Diagonal 5cm

how will i draw it
with both 5cm​

Answers

Answer:

that's easy

Step-by-step explanation:

first we should check the 5 cm in scale .

Then we can easily draw 5 cm in side and diagonal.

hope it's clear to you.

What is 23.2639 rounded to the nearest hundredth?

Answers

Answer:

23.26

Step-by-step explanation:

I hope is helps and I hope you get right but I tried at least.

Answer:

23.26

Step-by-step explanation:

A simple search on rounding calculator and i took the k-12 test and got it right

Please plssss pls I’ll award you so much points!! <3

Answers

Answer:

Part 1

1.) -105

2.) 120

3.) 15

4.) -200

5.) 40

6.) 16

7.) 240

Step-by-step explanation:

1.) Do 7 x 15, which is 105, then since 15 is a negative and 7 is positive, the product is negative.

2.) Do 5 x 24, which is 120, and sine both 5 and 24 are negative, they cancel each other out and the product is positive.

3.) Do 75 / 5, which is 15, and since both 75 and 5 are negative, they cancel each other out and the quotient is positive.

4.) Do 25 x 8, which is 200, and since 25 is negative and 8 is positive, the product is negative.

5.) Do 120 / 3, which is 40, and since both 120 and 3 are positive, the quotient stays positive.

6.) Do 80 / 5, which is 16, and since both 80 and 5 are negative, they cancel each other out and the quotient is positive.

7.) Do 16 x 15, which is 240, and since both 16 and 15 are negative, they cancel each other out and the product is positive.

Hope this helps <3

B.6-(5x-9)2 for x=1

Answers

Answer:

14

Step-by-step explanation:

Step 1:

6 - ( 5x - 9 ) 2       Equation

Step 2:

6 - ( 5 ( 1 ) - 9 ) 2     Input x

Step 3:

6 - ( 5 - 9 ) 2      Multiply

Step 4:

6 - ( - 4 ) 2        Subtract

Step 5:

6 - ( - 8 )      Multiply

Answer:

14        Add

Hope This Helps :)

Answer:

14

Step-by-step explanation:

1) 6-(5[1]-9)2

2) 6-(5-9)2

3) 6-(10-18)

4) 6-(-8)

5) 14

The average temperature at the South Pole is -49.62°C, and the average temperature at the North Pole is -34.68°C. How much higher is the average temperature at the North Pole than at the South Pole?
A.
-84.3°C
B.
-14.94°C
C.
14.94°C
D.
84.3°C

Answers

Answer:

i am pretty sure it's -14.92

Step-by-step explanation:

Answer:

B!!!

Step-by-step explanation:

The Law of Large Numbers states that as an experiment is repeated, the relative frequency of an event tends toward the real probability.
a. if the probability of a specific observed event is very small, it is unlikely that the assumption about the probability is correct.
b. the probability of obtaining a favorable outcome increases as the number of trials increases.
c. the sampling distribution of the sample mean will be approximately normally distributed as long as the sample size is sufficiently large.
d. the probability that an event will occur is derived from one's increasing knowledge of relevant circumstances.

Answers

Answer:

the probability of obtaining a favorable outcome increases as the number of trials increases

Step-by-step explanation:

The law of large numbers occupies an important place in probability statistics especially as it regards the outcome of experiments.

A simple statement of this law is that; when an experiment is independently repeated a large number of times, the average result, that is obtained is close to the expected value.

Hence, the probability of obtaining a favorable outcome increases as the number of trials increases.

let x be 3 and y be 4 and z is 5
x + y / xz

Answers

Answer:

7/15

Step-by-step explanation:

3 + 4 / 3 * 5

7 / 15

Answer:

[See Below]

Step-by-step explanation:

[tex]Hey~There![/tex]

_____________________

First we have to turn to into a proper equation:

[tex]3+4[/tex] ÷ [tex]3*5[/tex]

Now we solve the two parts:

[tex]3+4=7[/tex][tex]3*5=15[/tex]

Then we can divide:

[tex]7[/tex] ÷ [tex]15=0.466666667...[/tex]

_____________________

So your answer would be:

Full equation: [tex]3+4[/tex] ÷ [tex]3*5[/tex]Simplified Equation: [tex]7[/tex] ÷ [tex]15[/tex]Simplified Answer: [tex]0.47[/tex]

_____________________

[tex]Hope~this~helps~Mate!\\-Your~Friendly~Answerer,~Shane[/tex]

will give brainlist plz help its for my 9 week exam

a. 228
b. 229
c. 172
d. 171

Answers

Answer:

I think its 229

if you take how many yellow marbles he got out of 7 it would be 3/7 and then I divided 400 by 7 and got 57. something so I multiplied 3 times 57 and got 171. So if you take 400-171 you get 229

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