STA 261 Exam 2 Review Spring 2021

Question 1

The variability we expect to see from one random sample to another is called ______

Accepted Answer

the sampling error

Question 2

If P(A) is 0.35, then the complement of P(A) is

Accepted Answer

0.65

Question 3

Consider two events A and B. P(A) = 0.5, P(B) = 0.4, and P(A and B) = 0.2. Are A and B independent events?

Accepted Answer

Yes

Question 4

According to the Empirical Rule, approximately ____% of observations are 2 SDs from the mean.

Accepted Answer

95

Question 5

Question coming ... get ready!

Accepted Answer

II only

Question 6

Consider two events A and B. P(A) = 0.5, P(B) = 0.4, and P(A and B) = 0.2. Are A and B disjoint?

Accepted Answer

No

Question 7

Which of the following is NOT a property of the normal distribution?

Accepted Answer

It is centered at the mean of 0

Question 8

Question coming ... Get ready!

Accepted Answer

The numbers 1-5 indicate the person gets COVID, numbers 6-100 they do not

Question 9

#s1-5 indicate person gets COVID. Use table to run simulation and find the probability at least one person gets COVID.

Accepted Answer

30%

Question 10

Let X= the time it takes technical support staff to complete trouble shooting on a service call

Accepted Answer

This random variable is continuous.

Question 11

When bootstrapping the sample size of the bootstrap sample must be

Accepted Answer

the same size as the original sample

Question 12

Each attempt of a random phenomenon that generates an outcome is called a(n)

Accepted Answer

trial

Question 13

Bootstrapping requires sampling without replacement.

Accepted Answer

False

Question 14

Question coming ... get ready!

Accepted Answer

I, II and III

Question 15

Get ready ... question coming!

Accepted Answer

False

Question 16

The natural tendency of randomly drawn samples to differ is called sampling error

Accepted Answer

True

Question 17

Calculator needed...

Accepted Answer

0.0016

Question 18

Question coming... Get ready!

Accepted Answer

Selecting a member of your family

Question 19

Consider two events A and B. P(A) = 0.5, P(B) = 0.4, and P(A and B) = 0.2. Find P(A|B).

Accepted Answer

0.5

Question 20

Which of the following does not need to be checked to apply the Central Limit Theorem?

Accepted Answer

Nearly normal condition

Question 21

Consider two events A and B. P(A) = 0.5, P(B) = 0.4, and P(A and B) = 0.2 Find P(A or B).

Accepted Answer

0.7

Question 22

Calculator needed...

Accepted Answer

.643

Question 23

Question coming ... Get ready!

Accepted Answer

Select 6 #s from 1-100; each number will correspond to getting COVID or not

Question 24

What is the standard normal distribution?

Accepted Answer

N(0, 1)

Question 25

If the original sample is {A, A, B, C, E} which of the following can be a possible bootstrap sample?

Accepted Answer

{B, B, B, B, E}

Question 26

Let Y = # of dropped calls per day by customers of a particular cell phone provider. This RV is

Accepted Answer

discrete

Question 27

In order to use the CLT for proportions you need at least ___ successes and ___ failures

Accepted Answer

15

Question 28

The collection of all possible outcomes from a random phenomenon is referred to as the

Accepted Answer

sample space

Question 29

Question will appear below...

Accepted Answer

False

Question 30

The sampling distribution and distribution of the sample are synonymous.

Accepted Answer

False

Question 31

StatCrunch needed...

Accepted Answer

0.6915

Question 32

What % of viewers watched the commercials only?

Accepted Answer

23.5%

Question 33

Attending class and not attending class are examples of what?

Accepted Answer

all of the above

Question 34

The probability determined from the long run relative frequency of an event's occurrence is

Accepted Answer

experimental probability

Question 35

You see gray clouds & conclude there's a 75% chance of rain. This is what type of probability?

Accepted Answer

subjective

Question 36

StatCrunch needed...

Accepted Answer

628

Question 37

Question coming ... get ready!

Accepted Answer

I and III

Question 38

Question coming... Get ready!

Accepted Answer

The probability 1 or more people in your family gets COVID

Question 39

Of the viewers who did not watch the Super Bowl, what percentage was male?

Accepted Answer

45.2%

Question 40

Which of the following is an impossible event?

Accepted Answer

Get 100% on the exam if you don't know how to use StatCrunch.

Question 41

Question coming...get ready!

Accepted Answer

I, II, and III

Question 42

The following is a breakdown of TV viewers during the Super Bowl in 2007. What % was male?

Accepted Answer

48.8%

Question 43

A fair coin has come up "heads" 10 times in a row. The probability of getting "heads" on the next flip is

Accepted Answer

50%

Question 44

Computer needed...

Accepted Answer

.159

Question 45

Let Y = # of dropped calls per day experienced by customers of a particular cell phone provider

Accepted Answer

0.65

STA 261 Exam 2 Review Spring 2021

Questions 45

STA 261 Exam 2 Review Spring 2021

Questions 45