Question 1

____________ values of the standard deviation result in a normal curve that is wider and flatter.

Accepted Answer

A)  Smaller
B)  Equal
C)  Larger
D)  Uniform C

Question 2

If the distances between the ordered data values are proportional to the distances between the actual values,then the normal probability plot will be a straight line.

Accepted Answer

A) True 
 B)False  True

Question 3

The average time a subscriber spends reading the local newspaper is 49 minutes.Assume the standard deviation is 16 minutes and that the times are normally distributed.What is the probability a subscriber will spend at least 1 hour reading the paper?

Accepted Answer

A)  .9987
B)  .7549
C)  .2451
D)  .0013 C

Question 4

The life of a light bulb is exponentially distributed with a mean of 1,000 hours.What is the probability that the bulb will last less than 800 hours?

Accepted Answer

A)  .6321
B)  .5507
C)  .7135
D)  .4493

Question 5

The weight of a product is normally distributed with a mean of 5 ounces.A randomly selected unit of this product weighs 7.1 ounces.The probability of a unit weighing more than 7.1 ounces is .0014.The production supervisor has lost files containing various pieces of information regarding this process,including the standard deviation.Determine the value of the standard deviation for this process.

Accepted Answer

A)  1.67
B)  0.70
C)  2.10
D)  0.50

Question 6

The area under the curve of a valid continuous probability distribution must ____________.

Accepted Answer

A)  Equal 1
B)  Be between 0 and 1
C)  Be infinite
D)  Be less than 1

Question 7

The weight of a product is normally distributed with a standard deviation of .5 ounces.What should the average weight be if the production manager wants no more than 5 percent of the products to weigh more than 5.1 ounces?

Accepted Answer

A)  4.278
B)  4.409
C)  3.455
D)  5.922

Question 8

The thickness of a randomly selected metal piece is a ___________ random variable.

Accepted Answer

A)  Poisson
B)  Continuous
C)  Discrete
D)  Binomial

Question 9

An apple juice producer buys all his apples from a conglomerate of apple growers in one northwestern state.The amount of juice squeezed from each of these apples is approximately normally distributed with a mean of 2.25 ounces and a standard deviation of 0.15 ounce.What is the probability that a randomly selected apple will contain more than 2.50 ounces?

Accepted Answer

A)  .9525
B)  .4525
C)  .0475
D)  .5474

Question 10

Consider a normal population with a mean of 10 and a variance of 4.Find P(X < 6).

Accepted Answer

A)  .0228
B)  .1587
C)  .8413
D)  .9772

Question 11

In a statistical study,the random variable X = 1 if the house is colonial,and X = 0 if the house is not colonial.The random variable X is continuous.

Accepted Answer

A) True 
 B)False

Question 12

A continuous probability distribution that is useful in describing the time or space between successive occurrences of an event is a(n):

Accepted Answer

A)  Uniform probability distribution.
B)  Normal probability distribution.
C)  Poisson probability distribution.
D)  Exponential probability distribution.

Question 13

Find z when the area between z and -z is .9030.

Accepted Answer

A)  1.50
B)  1.30
C)  0.12
D)  1.66

Question 14

The life of a light bulb is exponentially distributed with a mean of 1,000 hours.What is the probability that the bulb will last more than 1,200 hours?

Accepted Answer

A)  .3012
B)  .3679
C)  .4345
D)  .6988

Question 15

The specific shape of each normal distribution is determined by its ____________ and ____________.

Accepted Answer

A)  Mean,standard deviation
B)  Median,standard deviation
C)  Mean,variance
D)  Median,variance

Question 16

The US local airport keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals.The stem-and-leaf plot of the data for one year is below. Compute the standardized quartile value O_i for i = 4.

Accepted Answer

The answer of The US local airport keeps track of...

Question 17

The weight of a product is normally distributed with a standard deviation of .5 ounces.What should the average weight be if the production manager wants no more than 10 percent of the products to weigh more than 4.8 ounces?

Accepted Answer

A)  3.52
B)  3.64
C)  5.44
D)  4.16

Question 18

The cashier service time at the local branch of the Rivertown bank has an exponential distribution with a mean of 2.5 minutes.What is the probability that the service time is no more than 3 minutes?

Accepted Answer

A)  .3012
B)  .6988
C)  .4346
D)  .5654
E)  .0821

Question 19

The relationship between the standard normal random variable z and normal random variable X is that:

Accepted Answer

A)  Only the normal random variable X is continuous.
B)  Only the standard normal variable z is continuous.
C)  The standard normal variable z counts the number of standard deviations that the value of the normal random variable X is away from its mean.
D)  The values of the standard normal random variable z cannot be negative.
E)  The values of the normal random variable X cannot be negative.

Question 20

The exponential probability distribution is based on a continuous random variable.

Accepted Answer

A) True 
 B)False

Exam 6: Continuous Random Variables

____________ values of the standard deviation result in a normal curve that is wider and flatter.

If the distances between the ordered data values are proportional to the distances between the actual values,then the normal probability plot will be a straight line.

The average time a subscriber spends reading the local newspaper is 49 minutes.Assume the standard deviation is 16 minutes and that the times are normally distributed.What is the probability a subscriber will spend at least 1 hour reading the paper?

The life of a light bulb is exponentially distributed with a mean of 1,000 hours.What is the probability that the bulb will last less than 800 hours?

The area under the curve of a valid continuous probability distribution must ____________.

The weight of a product is normally distributed with a standard deviation of .5 ounces.What should the average weight be if the production manager wants no more than 5 percent of the products to weigh more than 5.1 ounces?

The thickness of a randomly selected metal piece is a ___________ random variable.

Consider a normal population with a mean of 10 and a variance of 4.Find P(X < 6) .

In a statistical study,the random variable X = 1 if the house is colonial,and X = 0 if the house is not colonial.The random variable X is continuous.

A continuous probability distribution that is useful in describing the time or space between successive occurrences of an event is a(n) :

Find z when the area between z and -z is .9030.

The life of a light bulb is exponentially distributed with a mean of 1,000 hours.What is the probability that the bulb will last more than 1,200 hours?

The specific shape of each normal distribution is determined by its and .

The US local airport keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals.The stem-and-leaf plot of the data for one year is below. Compute the standardized quartile value O_i for i = 4.

The weight of a product is normally distributed with a standard deviation of .5 ounces.What should the average weight be if the production manager wants no more than 10 percent of the products to weigh more than 4.8 ounces?

The cashier service time at the local branch of the Rivertown bank has an exponential distribution with a mean of 2.5 minutes.What is the probability that the service time is no more than 3 minutes?

The relationship between the standard normal random variable z and normal random variable X is that:

The exponential probability distribution is based on a continuous random variable.

Exam 6: Continuous Random Variables

____________ values of the standard deviation result in a normal curve that is wider and flatter.

If the distances between the ordered data values are proportional to the distances between the actual values,then the normal probability plot will be a straight line.

The average time a subscriber spends reading the local newspaper is 49 minutes.Assume the standard deviation is 16 minutes and that the times are normally distributed.What is the probability a subscriber will spend at least 1 hour reading the paper?

The life of a light bulb is exponentially distributed with a mean of 1,000 hours.What is the probability that the bulb will last less than 800 hours?

The area under the curve of a valid continuous probability distribution must ____________.

The weight of a product is normally distributed with a standard deviation of .5 ounces.What should the average weight be if the production manager wants no more than 5 percent of the products to weigh more than 5.1 ounces?

The thickness of a randomly selected metal piece is a ___________ random variable.

Consider a normal population with a mean of 10 and a variance of 4.Find P(X < 6) .

In a statistical study,the random variable X = 1 if the house is colonial,and X = 0 if the house is not colonial.The random variable X is continuous.

A continuous probability distribution that is useful in describing the time or space between successive occurrences of an event is a(n) :

Find z when the area between z and -z is .9030.

The life of a light bulb is exponentially distributed with a mean of 1,000 hours.What is the probability that the bulb will last more than 1,200 hours?

The specific shape of each normal distribution is determined by its ____________ and ____________.

The US local airport keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals.The stem-and-leaf plot of the data for one year is below. Compute the standardized quartile value Oi for i = 4.

The weight of a product is normally distributed with a standard deviation of .5 ounces.What should the average weight be if the production manager wants no more than 10 percent of the products to weigh more than 4.8 ounces?

The cashier service time at the local branch of the Rivertown bank has an exponential distribution with a mean of 2.5 minutes.What is the probability that the service time is no more than 3 minutes?

The relationship between the standard normal random variable z and normal random variable X is that:

The exponential probability distribution is based on a continuous random variable.

The specific shape of each normal distribution is determined by its and .

The US local airport keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals.The stem-and-leaf plot of the data for one year is below. Compute the standardized quartile value O_i for i = 4.