Duplicate of AP Statistics CH 18-19 Review Quiz!

Question 1

If I half the sample size, what will happen to the Margin of error?

Accepted Answer

Increase

Question 2

Large samples give.

Accepted Answer

smaller sampling variability than small samples

Question 3

A confidence interval is .52 ± .11. Convert the interval format to (lower limit, upper limit)

Accepted Answer

(.41, .63)

Question 4

What is the confidence interval for approximately 95% confidence?

Accepted Answer

about 40.9% to 46.3%, about 38.3% to 49.0%

Question 5

Answer the following:

Accepted Answer

.0306

Question 6

ACT scores are approximately N(20.6, 4.8). Calculate the z-score for 20 students with a mean ACT score of 24

Accepted Answer

3.17

Question 7

A commute is Normally distributed, N(35, 15). Given, a random sample of 36 commuters. P(sample mean > 40)

Accepted Answer

.0228

Question 8

What sample size is necessary for an ME of 3% with p=.7 and a 99% confidence level?

Accepted Answer

1554

Question 9

Some people get p and p-hat confused. Which one represents the true population parameter?

Accepted Answer

p

Question 10

If the conditions for np≥10 and n(1-p)≥10 are met..

Accepted Answer

the sampling distribution model can be considered approximately Normal

Question 11

If a population is Normally distributed then the sample size..

Accepted Answer

does not matter

Question 12

We usually want statistics with..

Accepted Answer

low bias and low variability

Question 13

If μ = 60 and δ = 12 and n=36, what is the standard deviation of the sample mean?

Accepted Answer

2

Question 14

What is Z* for a 95% confidence interval?

Accepted Answer

1.96

Question 15

What conditions must be met to use a Normal Approximation for a Binomial distribution?

Accepted Answer

np ≥ 10 and nq ≥ 10

Question 16

If μ = 60 and ς = 12 and n=36, what is the mean of the sampling distribution?

Accepted Answer

60

Question 17

Answer the following:

Accepted Answer

(.66, .80)

Question 18

Which of the following is NOT a condition of the Central Limit Theorem?

Accepted Answer

The samples must be dependent. .

Question 19

What 4 things describe sampling distributions?

Accepted Answer

shape, center, spread, and outliers

Question 20

The Central Limit Theorem allows us to use normal probability to answer questions about..

Accepted Answer

sample means

Question 21

Scores on the ACT ~N(20.6, 4.8). Find the probability that a group of 36 seniors have a mean of at least 22.

Accepted Answer

0.04

Question 22

Facebook users have a mean = 338 friends with a right-skewed distribution and stand. dev. = 100

Accepted Answer

if n=60, μx = 338

Question 23

For a fixed confidence level, how large would n have to be to halve the margin of error?

Accepted Answer

4x as large

Question 24

What is the margin of error ?

Accepted Answer

it depends

Question 25

88% of students favor having cookies at lunch. If you sample 12 students

Accepted Answer

You cannot use a Normal Approximation because nq < 10

Question 26

The standard deviation of the sampling means can be found using the following formula.

Accepted Answer

σ/√n

Question 27

What z* is used for the 98% confidence interval?

Accepted Answer

2.3

Question 28

What is the critical value for a 90% confidence level?

Accepted Answer

1.645

Question 29

What's the z* critical value for a 92% confidence interval?

Accepted Answer

±1.75

Question 30

Which is not part of the Central Limit Theorem?

Accepted Answer

z-score = (value - mean)/standard deviation

Question 31

We want a confidence interval of ± 3% with 95% confidence. What do we do?

Accepted Answer

increase sample size to about 1100

Question 32

Which is most likely to be true?

Accepted Answer

I

Question 33

Clementines weigh 65 g on average with a st. dev. = 12 g. Which is more likely?

Accepted Answer

randomly choosing one clementine >70 grams

Question 34

What's the variable s stand for?

Accepted Answer

sample standard deviation

Question 35

What is the distribution of means of all possible samples of size n of a population?

Accepted Answer

Sampling Distribution

Question 36

What is p-hat?

Accepted Answer

.436

Question 37

A confidence interval is (.64, .70). Convert it to the format: estimate ± margin of error

Accepted Answer

.67 ± .03

Question 38

As the sample size increases, what happens to the shape of the distribution of the sample statistic?

Accepted Answer

Becomes approximately normal

Question 39

Answer the following:

Accepted Answer

.14

Question 40

What is the margin of error for 95% confidence?

Accepted Answer

0.054

Question 41

Facebook users have a mean = 338 friends with a right-skewed distribution and stand. dev. = 100

Accepted Answer

if n=60, shape of the sampling distribution model will be Normal., if n=60, shape of the sample will be right-skewed

Question 42

What is the standard error ?

Accepted Answer

0.027

Question 43

What sample size is necessary to get a ME of 5% with p = .4 with a 90% confidence level?

Accepted Answer

260

Question 44

A parameter is a...

Accepted Answer

number that describes the model of the population

Question 45

What's the variable p stand for?

Accepted Answer

population proportion

Question 46

A statistic is unbiased if..

Accepted Answer

mean of sampling distribution = to true parameter value

Duplicate of AP Statistics CH 18-19 Review Quiz!

Questions 46

Duplicate of AP Statistics CH 18-19 Review Quiz!

Questions 46