Question 1

Let Y be the number of the 12 male adults who are less than 62 inches tall. Determine the mean and standard deviation of Y.

Accepted Answer

The answer of Let Y be the number of the...

Question 2

A Poisson distribution is:

Accepted Answer

A)  relevant when we sample from a population with only two types of members. 
B)  relevant when we perform a series of independent, identical experiments with only two possible outcomes. 
C)  usually relevant when we are interested in the number of events that occur over a given interval of time 
D)  the cornerstone of statistical theory 
E)  all of these choices

Question 3

Given that Z is a standard normal random variable, P(-1.0  Z  1.5) is:

Accepted Answer

A)  0.7745 
B)  0.8413 
C)  0.0919 
D)  0.9332

Question 4

Find P(X = 2).

Accepted Answer

The answer of Find P(X = 2)....

Question 5

Find the probability that the number of arrivals between 4:00 and 5:00 P.M. is exactly two.

Accepted Answer

The answer of Find the probability that the number of...

Question 6

The public school system is interested in examining the probability of a child being late to school. The child is categorized as either late or not late. What type of distribution should the school use to examine this issue?

Accepted Answer

A)  ​binomial distribution 
B)  ​normal distribution 
C)  ​exponential distribution 
D)  ​Poisson distribution

Question 7

Find the probability that the number of arrivals between 3:30 and 4:00 P.M. is at least 10.

Accepted Answer

The answer of Find the probability that the number of...

Question 8

A random variable X is normally distributed with a mean of 175 and a standard deviation of 50. Given that X = 150, its corresponding Z- score is -0.50.

Accepted Answer

A) True 
 B)False

Question 9

If the random variable X is exponentially distributed with parameter  = 3, then P(X  2) , up to 4 decimal places, is:

Accepted Answer

A)  0.3333 
B)  0.5000 
C)  0.6667 
D)  0.0025

Question 10

What is the probability that at least one of the 20 new microwaves sold will require a warranty repair in the first 90 days?

Accepted Answer

The answer of What is the probability that at least...

Question 11

What is the probability that at least 20 customers, but fewer than 30 customers arrive at this checkout counter in a given hour?

Accepted Answer

The answer of What is the probability that at least...

Question 12

Given that the random variable X is normally distributed with a mean of 80 and a standard deviation of 10, P(85  X  90) is:

Accepted Answer

A)  0.5328 
B)  0.3413 
C)  0.1915 
D)  0.1498

Question 13

Sampling done without replacement means that:

Accepted Answer

A)  only certain members of the population can be sampled 
B)  each member of the population can be sampled repeatedly 
C)  each member of the population can be sampled only once 
D)  each member of the population can be sampled twice

Question 14

Which distribution is best-suited to measure the length of time between arrivals at a grocery checkout counter?

Accepted Answer

A)  uniform 
B)  normal 
C)  exponential 
D)  Poisson

Question 15

Find the mean and the variance of X.

Accepted Answer

The answer of Find the mean and the variance of...

Question 16

What is the probability that exactly half the male adults will be less than 62 inches tall?

Accepted Answer

The answer of What is the probability that exactly half...

Question 17

Which probability distribution applies to the number of events occurring within a specified period of time or space?

Accepted Answer

A)  binomial distribution 
B)  Poisson distribution 
C)  any discrete probability distribution 
D)  any continuous probability distribution

Question 18

Using the standard normal curve, the Z- score representing the 10th percentile is 1.28.

Accepted Answer

A) True 
 B)False

Question 19

What is the variance of the time it takes a technician to fix a computer problem?

Accepted Answer

The answer of What is the variance of the time...

Question 20

What is the probability that at most two of the 20 new microwaves sold will require a warranty repair in the first 90 days?

Accepted Answer

The answer of What is the probability that at most...

Exam 5: Normal, Binomial, Poisson, and Exponential Distributions