why are convenience samples are not desirable?
Answer:
The disadvantages: Convenience samples do not produce representative results. If you need to extrapolate to the target population, convenience samples aren't going to get you there. ... Much larger convenience samples are not more accurate than small probability samples.
A large stockpile of used pumps contains 20% that are currently unusable and need to be repaired. A repairman is sent to the stockpile with three repair kits. He selects pumps at random and tests them one at a time. If a pump works, he goes on to the next one. If a pump doesn't work, he uses one of his repair kits on it. Suppose that it takes 10 minutes to test whether a pump works, and 20 minutes to repair a pump that does not work. The expected value and variance of the total time it takes the repairman to use up his three kits are, respectively:____.
Answer:
Expected value = 190
Variance = 4000
Step-by-step explanation:
Let X be the number of the trials until the third success of the bad pump.
This implies that X is a negative binomial distribution having θ = 20% = 0.2.
Now, if for example it will take X trials to use up the three pumps, then the total time is 10 min/trials + extra 10 minutes for the 3 bad pumps
This means the total time is written as;
T = 10X + (10 + 10 + 20)
T = 10X + 40
Mean which is also expected value of X is;
μ_x = 3/0.2 = 15
Variance of X is; σ²_x = 40
Thus;
Mean of T will be;
μ_T = 10μ_x + 40
μ_T = 10(15) + 40
μ_T = 190
Also, variance of T will be;
σ²_T = 10²•σ²_x
σ²_T = 100 × 40
σ²_T = 4000
What is the product of 3x(x2 + 4)?
O x2 + 3x + 4
O 3.3 + 4
O 3.3 + 12x
O 3.x2 + 12x
Answer:
The fourth option
Asha accidentally tore her factor table for the number 48.
Which list below contains all of the factors missing from Asha’s table?
Answer:
Top right
Step-by-step explanation:
What is X. PLEASE HELP I GIVE BRAINLEIEST
Answer:
x=60
Step-by-step explanation:
Hope this helped.
Nina rented a bicycle while she was on vacation she paid a flat rental fee of $75.00
Plus $9.50 each day the total cost was $450 write an equation you can use to find the number of days she rented the bicycle
Answer:
75.00+9.50d=450
Step-by-step explanation:
75 dollars to start off with plus 9.50 dollars a day is equal to 450 dollars in total
I need help on these problems!! Please help
Answer:
1. 6cm
2. 14cm
3. 12cm
4. 8cm
5. 9cm
6. 5cm
Step-by-step explanation:
Hope this helps
what is 300cm x 3,000cm - 789
Answer:
899211cm
Step-by-step explanation:
Answer:
899211
Step-by-step explanation:
300x3000=900000
900000-789=899211
Round to the nearest tenth
Answer:
Should be 36
Step-by-step explanation:
1. a^2 + 48^2= 60^2
2. a^2 + 2304 = 3600
3. Simplify: a^2 = 1296
4. Find the sqrt which is 36
...................Simplify 43.45
Answer:
9.31st 91 35 5789 400th
Step-by-step explanation:
43.45+567=
9.3
There are 75 students enrolled in camp. The day before the camp begins, 8℅ of the students cancel. how many students actually attend the camp?
Ally's Fitbit tells her she has completed 73% of her goal for number of steps taken
today. If she has taken 5,840 steps, what is Ally's goal for the day
Answer:
7416.8
Step-by-step explanation:
5,840 x 127%
Since she's 73 percent of the way there, we need to add the last 27 percent as well as put a one in front so it will work.
127%
Because this is not just 7416 steps you should consider rounding it if your teacher asks you to.
I will give brainliest to who answers RIGHT.
Answer:
RIGHT
Step-by-step explanation:
Write an absolute value equation for the following graph *picture attached *
Answer:
What is the difference between the absolute values of 3 and 9?
Step-by-step explanation:
Absolute value of 3: 3
Absolute value of 9: 9
9 - 3 = 6
I dont know if this helped but im hoping it does
(This is fundamental Counting principle) choosing from 35 different flavors of ice cream; one, two or three scoops; and sugar or waffle cone.
Answer:
210
Step-by-step explanation:
35x3x2=210
What does Sen π mean
Answer:Succinctly, pi—which is written as the Greek letter for p, or π—is the ratio of the circumference of any circle to the diameter of that circle. ... In decimal form, the value of pi is approximately 3.14.
Step-by-step explanation:
a cash prize of $4,800 is awarded at a fundraiser. if 1200 ticket's are sold at $9 each find the expected value
Answer:
is 10,800
Step-by-step explanation: you multiply 1,200 x 9
Write an equation of the line passing through the given point (5,−5) and having the given
slope m=−9. Write the final answer in slope-intercept form.
Answer:
y=-9x+40
Step-by-step explanation:
y-y1=m(x-x1)
y-(-5)=-9(x-5)
y+5=-9x+45
y=-9x+45-5
y=-9x+40
complete the equation of the line through ( 3,1) and ( 4,7) .
can someone else help me pleased .
Answer: y = mx + b m = 8 b = -25
Step-by-step explanation:
Compare and contrast the words malfunction and dysfunction
Twice the sum of - 6 and a number is the same as the number decreased by
4
Find the number
A library had a used book sale for 4 days. The library paid $25 for an advertisement each day of the sale and sold each book (b) for $2.00. The expression below represents the amount of money the library raised at the book sale. How much money was raised when 400 books were sold per day?
Answer:
1,982
Step-by-step explanation:
i got It right on edge 2020
The library raised $320,100 when 400 books were sold per day.
What is an expression?An expression contains one or more terms with addition, subtraction, multiplication, and division.
We always combine the like terms in an expression when we simplify.
We also keep all the like terms on one side of the expression if we are dealing with two sides of an expression.
Example:
1 + 3x + 4y = 7 is an expression.
3 + 4 is an expression.
2 x 4 + 6 x 7 – 9 is an expression.
33 + 77 – 88 is an expression.
We have,
Number of days book sale = 4
The library paid for advertisement each day = $25
Cost of each book (b) = $2.00.
The expression represents the amount of money the library raised at the book sale.
= 4(25) + 2b(400)
Now,
Substitute b = 400 into the expression.
= 4(25) + 2(400)(400)
= 4(25) + 320000
= 320100
Therefore,
The library raised $320,100 when 400 books were sold per day.
Learn more about expressions here:
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please help me please
Step-by-step explanation:
I think I did the right process but the answer didn't match.
Which of the binomials below is a factor of this trinomial?
3y2 + 18x+ 24
twice a number is seven more than the number itself
Answer:
I think it is 2x(7 + x)
Step-by-step explanation:
i am wrong, im so sorry
I need help please. Show your steps
Answer:
i dont know how anyone could answer this lol you're f u ck ed
Step-by-step explanation:
Where is the blue dot on the number line?
Answer:
on the number line the blue dot is co ordinate 4.9
The point is on the x-axis and 17 units to the left of the y-axis.
Answer:
02383923892
Step-by-step explanation:
The coordinates values of the point is (- 17, 0).
What is an ordered pair?An ordered pair is made up of the ordinate and the abscissa of the x coordinate, with two values given in parenthesis in a certain sequence.
Pair in Order = (x, y)
x is the abscissa, the distance measure of a point from the primary axis x
y is the ordinate, the distance measure of a point from the secondary axis y
Given, The point is on the x-axis and 17 units to the left of the y-axis.
Now, the value of y at the y-axis is 0 and the point is 17 units left to it so it should be - 17.
So, the coordinate points are (- 17, 0).
learn more about ordered pairs here :
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Evaluate: 13 × 20 – 15 × 9 + 20 × 7 – 6 × 15.
Answer:
175
Step-by-step explanation:
13 × 20 – 15 × 9 + 20 × 7 – 6 × 15 = 175
Nester needs a cover for his circular outdoor pool. The circumference of the cover must be 16 meters. Which quantity is closest to the area of the pool cover measured in square meter?
Answer: 200.96
A - C/r, d = 16 ⇒ r = 8
A = (16π/2) (8)
= 8π (8) = 64π
A = 64 (3.14) ?
64 (3.14) = 200.96