1) In a 'normal distribution'

a.

the amount of scores that are not of use for statistical analyses.

b.

the mean, median, and mode have similar values.

c.

the portion of the distribution falling between the mean value and one standard deviation above the mean value includes roughly one-third of all scores in the distribution.

d.

it is possible to draw a line down through any point, and know the percentage of scores falling on each side of the line.

2) Outcome is .........................................

a.

the result of a single trial in a probability experiment.

b.

of one or more outcomes and is a subset of the sample space.

c.

the set of all possible outcomes of a probability experiment.

d.

an action, or trial, through which specific results (counts, measurements, or responses) are obtained.

3) A state's department of transportation plans to develop a new section of interstate highway and receives 16 bids for the project. The state plans to hire four of the bidding companies. How many different combinations of four companies can be selected from the 16 bidding companies?

a.

1280

b.

1820

c.

128

d.

82

4) An education finance corporation claims that the average credit card debts carried by undergraduates are normally distributed, with a mean of $3173 and a standard deviation of $1120. What is the probability that a randomly selected undergraduate, who is a credit card holder, has a credit card balance of less than $2700?

a.

0.7332

b.

0.3372

c.

0.7243

d.

0.2723

5) If P (A) = 0.8, P (B) = 0.7 and P (A|B) = 0.6, what is P (A and B) ?

a.

0.24

b.

0.52

c.

0.42

d.

0.15

6)

6) Abraham de Moivre, a French mathematician, derived the ...................... distribution.

a.

uniform

b.

hypergeometry

c.

binomial

d.

normal

7) Two events, A and B, are said to be independent if:

a.

P (B|A) = P (A)

b.

P (A and B) = P (A) + P (B)

c.

P (A and B) = P (A) . P (B)

d.

P (A|B) = P (B)

8) Find the cumulative area that corresponds to a z-score of 1.15.

a.

0.8749

b.

0.1256

c.

0.3452

d.

0.9115

9) You roll a six-sided dice. Find the probability of rolling a number less than 5.

a.

0.555

b.

0.667

c.

0.833

d.

0.167

10) A survey indicates that people use their cellular phones an average of 1.5 years before buying a new one. The standard deviation is 0.25 year. A cellular phone user is selected at random. Find the probability that the user will use their current phone for less than 1 year before buying a new one. Assume that the variable x is normally distributed.

a.

0.0228

b.

0.8002

c.

0.8022

d.

0.2208

11) A bag contains 5 red balls, 6 white balls, 7 green balls, 8 black balls. One ball is drawn at random from the bag. Find the probability that the ball drawn is black or red.

a.

0.91

b.

0.19

c.

0.05

d.

0.5

12) Which of the following cannot generate a Poisson distribution?

a.

The number of telephone calls received in a ten-minute interval

b.

The number of customers arriving at a petrol station

c.

The number of bacteria found in a cubic yard of soil

d.

The number of cars arriving at a parking garage in a one-hour time interval