1) which of the

following statements about the median is not true?

- a. it is more affected by extreme values

than the mean. - b.

it is a measure of central tendency. - c.

it is equal to Q2 - it

is equal to the mode in bell-shaped “normal” distributions.

2) according to the

empirical rule, if the data form a “bell-shaped” normal distribution, ____

percent of the observations will be contained within 2 standard deviations

around the mean.

a.

68.26

b.

88.89

c.

93.75

d.

95.44

Table 3-1

health care issues

are receiving much attention in both academic and political arenas. A

sociologist recently conducted a survey of citizens over 60 years of age whose

net worth is too high to qualify for medicaid and have no private health

insurance. the ages of 25 uninsured senior citizens were as follows:

60 61 62 63 64 65 66

68 68 69 70 73 73 74 75 76 76 81 81 82 86 87 89 90 92

3) Referring to table

3-1 identify which of the following is the correct statement.

a.

one fourth of the senior citizens sampled are

below 65.5 years of age.

b.

the middle 50% of the senior citizens sampled are between 65.5 and 73.0

years of age.

c.

the average age of senior citizens sampled is 73.5 years of age.

d.

all of the above are correct.

4) Selection of

raffle tickets from a large bowl is an example of:

a.

sampling with replacement

b.

sampling without replacement

c.

subjective probability

d.

none of the above.

5) the collection of

all possible events is called.

a.

a simple probability.

b.

a sample space.

c.

a joint probability.

d.

the null set.

6) A business venture

can result in the following outcomes (with their corresponding chance of

occurring in parentheses) : Highly Successful (10%), Successful (25%) Break

Even (25%) Disappointing (20%), and Highly Disappointing (?). If these are the

only outcomes possible for the business venture, what is the chance that the

business venture will be considered Highly Disappointing?

a.

10%

b.

15%

c.

20%

d.

25%

7) The probability

that house sales will increase in the next 6 months is estimated to be 0.25.

The probability that the interest rates on housing loans will go up in the same

period is estimated to be 0.74. the probability that house sales or interest

rates will go up during the next 6 months is estimated to be 0.89. the events

of increase in house sales and increase in interest rates in next 6 months are:

a.

statistically independent.

b.

mutually exclusive

c.

collectively exhaustive

d.

none of the above

8) The probability

that a new advertising campaign will increase sales is assessed as being 0.80.

The probability that the cost of developing the new ad campaign can be kept

within the original budget allocation is 0.40. Assuming that the two events are

independent, the probability that the cost is not kept within budget or the

campaign will not increase sales is:

a.

0.12

b.

0.32

c.

0.68

d.

0.88

9) What type of

probability distribution will most likely be used to analyze the number of

chocolate chip parts per cookie in the following problem?

The quality control

manager of Marilyn’s cookies is inspecting a batch of chocolate chip cookies.

When the production process is in control, the average number of chocolate chip

parts per cookie is 6.0. The manager is interested in analyzing the probability

that any particular cookie being inspected has fewer than 5.0 chip parts.

a.

binomial distribution

b.

poisson distribution

c.

normal distribution

d.

hypergeometric distribution

Table 4-1

Mothers against drunk

driving is a very visible group whose main focus is to educate the public about

the harm caused by drunk drivers. A study was recently done that emphasized the

problem we all face with drinking and driving. four hundred accidents that

occurred on a saturday night were analyzed. two items noted were the number of

vehicles involved and whether alcohol played a role in the accident. the

numbers are shown below:

Did alcohol play a

role? number of vehicles involved

totals

1

2

3

yes

50

100

20

170

no

25

175

30

230

totals

75

275

50

400

10) referring to

table 4-1, what proportion of accidents involved alcohol and a single vehicle?

a.

25/400

b.

50/400

c.

195/400

d.

245/400

11) If the

expectation of a sampling distribution is located at the parameter it is

estimating, then we call that sampling distribution.

a.

unbiased.

b.

minimum variance

c.

biased

d.

random

12) for air travelers,

one of the biggest complaints is of the waiting time between when the airplane

taxis away from the terminal until the flight takes off. this waiting time is

known to have a skewed-right distribution with a mean of 10 minutes and a

standard deviation of 8 minutes. Supposed 100 flights have been randomly

sampled. Describe the sampling distribution of the mean waiting time between

when the airplane taxis away from the terminal until the flight takes off for

these 100 flights.

a.

distribution is skewed-right with mean = 10 minutes and standard error =

0.8 minutes.

b.

distribution is skewed-right with mean = 10 minutes and standard error =

8 minutes

c.

distribution is approximately normal with mean

= 10 minutes and standard error = 0.8 minutes

d.

distribution is approximately normal with mean = 10 minutes and standard

error = 8 minutes.

13) Which of the

following statements about the sampling distribution of the sampling

distribution of the sample mean is **incorrect**?

a.

the sampling distribution of the sample mean is approximately normal

whenever the sample size is sufficiently large (n>_ 30)

b.

the sampling distribution of the sample mean is generated by repeatedly

taking samples of size n and computing the sample means.

c.

the mean of the sampling distribution of the sample mean is equal to U.

d.

thestandard deviation of

the sampling distribution of the sample mean is equal to O (squiggly upper)

14) .. why is the

central limit theorem so important to the study of sampling distributions?

a.

it allows us to disregard the size of the sample selected when the

population is not normal.

b.

it allows us to disregard the shape of the sampling distribution when

the size of the population is large.

c.

it allows us to disregard the size of the population we are sampling

from.

d.

it allows us to disregard the shape of the

population when n is large.

15)

supposed a sample of

n=50 items is drawn from a population of manufactured products and the weight,

x, of each item is recorded. prior experience has shown that the weight has a

probability distribution with U =6 ounces and O = 2.5 ounces. which of the

following is true about the sampling distribution of the sample mean if a

sample of size 15 is selected?

a.

the mean of the sampling

distribution is 6 ounces

b.

the standard deviation of the sampling distribution is 2.5 ounces

c.

the shape of the sample distribution is approximately normal.

d.

all of the above are correct.

16.

major league baseball

salaries average $1.5 million with a standard deviation of $0.8 million in

1994. Suppose a sample of 100 major league players was taken. find the

approximate probability that the average salary of the 100 players exceeded $1

million.

a.

approximately 0

b.

0.2357

c.

0.7357

d.

approximately 1

17.

the standard error of

the proportion will become larger

a.

as p approaches 0.

b.

as p approaches 0.50

c.

as p approaches 1.00

d.

as n increases.

18.

Table 5-6

the mean selling

price of new homes in a city over a year was $115,000. the population standard

deviation was $25,000. a random sample of 100 new home sales from this city was

taken.

referring to table

5-6, without doing the calculations, state in which of the following ranges the

sample selling price is most likely to lie.

a.

$113,000 — $115,000

b.

$114,000 — $116,000

c.

$115,000 — $117,000

d.

$116,000 — $118,000

19.

which of the

following is **not** true about the student’s t distribution?

a.

it has more area in the tails and less in the center than does the

normal distribution.

**b.
**it is used to construct confidence intervals

for the population mean when the population standard deviation is known

**.**

c.

it is bell shaped and symmetrical

d.

as the number of degrees of freedom increases, the t distribution

approaches the normal distribution.

20.

The head librarian at

the library of congress has asked her assistant for an interval estimate of the

mean number of books checked out each day. the assistant provides the following

interval estimate: from 740 to 920 books per day. if the head librarian knows

that the population standard deviation is 150 books checked out per day, and

she asked her assistant to use 25 days of data to construct the interval

estimate, what confidence level can she attache to the interval estimate?

a.

99.7%

b.

99.0%

c.

98.0%

d.

95.4%

???

4) Selection of

raffle tickets from a large bowl is an example of:

- sampling

with replacement

f.

sampling without replacement

g.

subjective probability

h.

none of the above.

5) the collection of

all possible events is called.

- a

simple probability.

f.

asample space.

g.

a joint probability.

h.

the null set.