Question 1

If x is a normal random variable with mean ($\mu$)equal to 80 and a standard deviation ($\sigma$)of 5, the z score for x = 88 is ___.

Accepted Answer

A) 1.8 
B) -1.8 
C) 1.6 
D) -1.6 
E) 8.0 
A) 1.8 
B) -1.8 
C) 1.6 
D) -1.6 
E) 8.0

Question 2

Inquiries arrive at a record message device according to a Poisson process at a rate of 15 inquiries per minute.The probability that it takes more than 12 seconds for the first inquiry to arrive is approximately _________

Accepted Answer

A) 0.05 
B) 0.75 
C) 0.25 
D) 0.27 
E) 0.73 
A) 0.05 
B) 0.75 
C) 0.25 
D) 0.27 
E) 0.73

Question 3

Participants in a 2-day biking event, cross the finish line at a rate of 10 bike riders per fifteen minute interval.On average, how much time, in minutes, elapses between bike riders?

Accepted Answer

A) 1.50 
B) .0667 
C) .1667 
D) 1.00 
E) 2.50 
A) 1.50 
B) .0667 
C) .1667 
D) 1.00 
E) 2.50

Question 4

If the probability of a binomial distribution was considering values that were less than 14, then the correction for continuity would start at 13.5.

Accepted Answer

A) True 
 B)False

Question 5

The probability that a call to an emergency help line is answered in less than 10 seconds is 0.8.Assume that the calls are independent of each other.Using the normal approximation for binomial with a correction for continuity, the probability that at least 75 of 100 calls are answered within 10 seconds is approximately _______

Accepted Answer

A) 0.8 
B) 0.1313 
C) 0.5235 
D) 0.9154 
E) 0.8687 
A) 0.8 
B) 0.1313 
C) 0.5235 
D) 0.9154 
E) 0.8687

Question 6

Sure Stone Tire Company has established that the useful life of a particular brand of its automobile tires is normally distributed with a mean of 40,000 kilometres and a standard deviation of 5000 kilometres.What is the probability that a randomly selected tire of this brand has a life between 30,000 and 50,000 kilometres?

Accepted Answer

A) 0.5000 
B) 0.4772 
C) 0.9544 
D) 0.9772 
E) 1.0000 
A) 0.5000 
B) 0.4772 
C) 0.9544 
D) 0.9772 
E) 1.0000

Question 7

If x is uniformly distributed over the interval 8 to 12, inclusively (8 $\le$ x $\le$ 12), then the probability, P(9 $\le$ x $\le$ 11), is ___.

Accepted Answer

A) 0.250 
B) 0.500 
C) 0.333 
D) 0.750 
E) 1.000 
A) 0.250 
B) 0.500 
C) 0.333 
D) 0.750 
E) 1.000

Question 8

A recent market study has determined that the probability that a young adult would be willing to try a new online financial service that your company is offering is 50%.In a random sample of 10 young adults, the approximate probability that at least 2 but no more than 3 will be willing to try this new service is _________.

Accepted Answer

A) 0.1575 
B) 0.1612 
C) 0.1775 
D) 0.1812 
E) 0.1975 
A) 0.1575 
B) 0.1612 
C) 0.1775 
D) 0.1812 
E) 0.1975

Question 9

If x, the time (in minutes)to complete an oil change job at a certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 $\le$ x $\le$30), then the standard deviation of this distribution is ___.

Accepted Answer

A) unknown 
B) 8.33 
C) 0.833 
D) 2.89 
E) 1.89 
A) unknown 
B) 8.33 
C) 0.833 
D) 2.89 
E) 1.89

Question 10

The average time between phone calls arriving at a call centre is 30 seconds.Assuming that the time between calls is exponentially distributed, find the probability that less than two minutes elapse between calls.

Accepted Answer

A) 0.018 
B) 0.064 
C) 0.936 
D) 0.982 
E) 1.000 
A) 0.018 
B) 0.064 
C) 0.936 
D) 0.982 
E) 1.000

Question 11

Most graduate business schools require applicants to take the GMAT.Scores on this test are approximately normally distributed with a mean of 545 points and a standard deviation of 100 points.What score do you need to be in the top 5% (approximately the scores needed for top schools)?

Accepted Answer

A) 718 
B) 716 
C) 714 
D) 712 
E) 710 
A) 718 
B) 716 
C) 714 
D) 712 
E) 710

Question 12

The total area underneath any normal curve is equal to ___.

Accepted Answer

A) the mean 
B) one 
C) the variance 
D) the coefficient of variation 
E) the standard deviation 
A) the mean 
B) one 
C) the variance 
D) the coefficient of variation 
E) the standard deviation

Question 13

Suppose you are working with a data set that is normally distributed with a mean of 400 and a standard deviation of 20.Determine the value of x such that 60% of the values are greater than x.

Accepted Answer

A) 404.5 
B) 395.5 
C) 405.0 
D) 395.0 
E) 415.0 
A) 404.5 
B) 395.5 
C) 405.0 
D) 395.0 
E) 415.0

Question 14

Since a normal distribution curve extends from minus infinity to plus infinity, the area under the curve is infinity.

Accepted Answer

A) True 
 B)False

Question 15

Let x be a binomial random variable with n=20 and p=.8.If we use the normal distribution to approximate probabilities for this, we would use a mean of ___.

Accepted Answer

A) 20 
B) 16 
C) 3.2 
D) 8 
E) 5 
A) 20 
B) 16 
C) 3.2 
D) 8 
E) 5

Question 16

Employees arrive at a cafeteria according to a Poisson process at an average rate of 30 employees per hour.The probability that after one employee arrives, the next one will arrive at least 3 minutes later is _________.

Accepted Answer

A) 0.223 
B) 0.202 
C) 0.183 
D) 0.162 
E) 0.143 
A) 0.223 
B) 0.202 
C) 0.183 
D) 0.162 
E) 0.143

Question 17

If x is uniformly distributed over the interval 8 to 12, inclusively (8 $\le$ x $\le$ 12), then P(x < 7)is ___.

Accepted Answer

A) 0.500 
B) 0.000 
C) 0.375 
D) 0.250 
E) 1.000 
A) 0.500 
B) 0.000 
C) 0.375 
D) 0.250 
E) 1.000

Question 18

The probability that someone will prefer Coke over Pepsi is 0.56.A researcher asked 90 people which soda pop they preferred, and used the normal approximation to the binomial with a correction for continuity, what would be the probability at least 50 preferring Coke?

Accepted Answer

A) 0.615 
B) 0.507 
C) 0.560 
D) 0.900 
E) 0.576 
A) 0.615 
B) 0.507 
C) 0.560 
D) 0.900 
E) 0.576

Question 19

Suppose the total time to fill a routine prescription at a local pharmacy averages 35 minutes starting from the time the physician places the order to the time it is dispensed.Assume the standard deviation is 11 minutes.The z-score for x = 46 is ________.

Accepted Answer

A) 1.0 
B) -1.0 
C) 11 
D) -11 
E) .10 
A) 1.0 
B) -1.0 
C) 11 
D) -11 
E) .10

Question 20

If x, the time (in minutes)to complete an oil change job at a certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 $\le$ x $\le$ 30), then the probability that an oil change job will be completed 24 minutes or more, i.e., P(x $\ge$24)is ___.

Accepted Answer

A) 0.100 
B) 0.000 
C) 0.333 
D) 0.600 
E) 1.000 
A) 0.100 
B) 0.000 
C) 0.333 
D) 0.600 
E) 1.000

If x is a normal random variable with mean ( $\mu$ )equal to 80 and a standard deviation ( $\sigma$ )of 5, the z score for x = 88 is ___.

Inquiries arrive at a record message device according to a Poisson process at a rate of 15 inquiries per minute.The probability that it takes more than 12 seconds for the first inquiry to arrive is approximately _________

Participants in a 2-day biking event, cross the finish line at a rate of 10 bike riders per fifteen minute interval.On average, how much time, in minutes, elapses between bike riders?

If the probability of a binomial distribution was considering values that were less than 14, then the correction for continuity would start at 13.5.

If x is uniformly distributed over the interval 8 to 12, inclusively (8 $\le$ x $\le$ 12), then the probability, P(9 $\le$ x $\le$ 11), is ___.

If x, the time (in minutes)to complete an oil change job at a certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 $\le$ x $\le$ 30), then the standard deviation of this distribution is ___.

The average time between phone calls arriving at a call centre is 30 seconds.Assuming that the time between calls is exponentially distributed, find the probability that less than two minutes elapse between calls.

Most graduate business schools require applicants to take the GMAT.Scores on this test are approximately normally distributed with a mean of 545 points and a standard deviation of 100 points.What score do you need to be in the top 5% (approximately the scores needed for top schools)?

The total area underneath any normal curve is equal to ___.

Suppose you are working with a data set that is normally distributed with a mean of 400 and a standard deviation of 20.Determine the value of x such that 60% of the values are greater than x.

Since a normal distribution curve extends from minus infinity to plus infinity, the area under the curve is infinity.

Let x be a binomial random variable with n=20 and p=.8.If we use the normal distribution to approximate probabilities for this, we would use a mean of ___.

Employees arrive at a cafeteria according to a Poisson process at an average rate of 30 employees per hour.The probability that after one employee arrives, the next one will arrive at least 3 minutes later is _________.

If x is uniformly distributed over the interval 8 to 12, inclusively (8 $\le$ x $\le$ 12), then P(x < 7)is ___.

The probability that someone will prefer Coke over Pepsi is 0.56.A researcher asked 90 people which soda pop they preferred, and used the normal approximation to the binomial with a correction for continuity, what would be the probability at least 50 preferring Coke?

Suppose the total time to fill a routine prescription at a local pharmacy averages 35 minutes starting from the time the physician places the order to the time it is dispensed.Assume the standard deviation is 11 minutes.The z-score for x = 46 is ________.

If x, the time (in minutes)to complete an oil change job at a certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 $\le$ x $\le$ 30), then the probability that an oil change job will be completed 24 minutes or more, i.e., P(x $\ge$ 24)is ___.

Introduction to Statistics

Charts and Graphs

Descriptive Statistics

Probability

Discrete Distributions

Sampling and Sampling Distributions

Statistical Inference: Estimation for Single Populations

Statistical Inference: Hypothesis Testing for Single Populations

Statistical Inferences About Two Populations

Analysis of Variance and Design of Experiments

Simple Regression Analysis and Correlation

Multiple Regression Analysis

Building Multiple Regression Models

Time-Series Forecasting and Index Numbers

Analysis of Categorical Data

Nonparametric Statistics

Statistical Quality Control

Decision Analysis

Filters

Exam 6: Continuous Distributions

If x is a normal random variable with mean ( μ\muμ )equal to 80 and a standard deviation ( σ\sigmaσ )of 5, the z score for x = 88 is ___.

Inquiries arrive at a record message device according to a Poisson process at a rate of 15 inquiries per minute.The probability that it takes more than 12 seconds for the first inquiry to arrive is approximately _________

Participants in a 2-day biking event, cross the finish line at a rate of 10 bike riders per fifteen minute interval.On average, how much time, in minutes, elapses between bike riders?

If the probability of a binomial distribution was considering values that were less than 14, then the correction for continuity would start at 13.5.

If x is uniformly distributed over the interval 8 to 12, inclusively (8 ≤\le≤ x ≤\le≤ 12), then the probability, P(9 ≤\le≤ x ≤\le≤ 11), is ___.

If x, the time (in minutes)to complete an oil change job at a certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 ≤\le≤ x ≤\le≤ 30), then the standard deviation of this distribution is ___.

The average time between phone calls arriving at a call centre is 30 seconds.Assuming that the time between calls is exponentially distributed, find the probability that less than two minutes elapse between calls.

Most graduate business schools require applicants to take the GMAT.Scores on this test are approximately normally distributed with a mean of 545 points and a standard deviation of 100 points.What score do you need to be in the top 5% (approximately the scores needed for top schools)?

The total area underneath any normal curve is equal to ___.

Suppose you are working with a data set that is normally distributed with a mean of 400 and a standard deviation of 20.Determine the value of x such that 60% of the values are greater than x.

Since a normal distribution curve extends from minus infinity to plus infinity, the area under the curve is infinity.

Let x be a binomial random variable with n=20 and p=.8.If we use the normal distribution to approximate probabilities for this, we would use a mean of ___.

Employees arrive at a cafeteria according to a Poisson process at an average rate of 30 employees per hour.The probability that after one employee arrives, the next one will arrive at least 3 minutes later is _________.

If x is uniformly distributed over the interval 8 to 12, inclusively (8 ≤\le≤ x ≤\le≤ 12), then P(x < 7)is ___.

The probability that someone will prefer Coke over Pepsi is 0.56.A researcher asked 90 people which soda pop they preferred, and used the normal approximation to the binomial with a correction for continuity, what would be the probability at least 50 preferring Coke?

Suppose the total time to fill a routine prescription at a local pharmacy averages 35 minutes starting from the time the physician places the order to the time it is dispensed.Assume the standard deviation is 11 minutes.The z-score for x = 46 is ________.

Introduction to Statistics

Charts and Graphs

Descriptive Statistics

Probability

Discrete Distributions

Sampling and Sampling Distributions

Statistical Inference: Estimation for Single Populations

Statistical Inference: Hypothesis Testing for Single Populations

Statistical Inferences About Two Populations

Analysis of Variance and Design of Experiments

Simple Regression Analysis and Correlation

Multiple Regression Analysis

Building Multiple Regression Models

Time-Series Forecasting and Index Numbers

Analysis of Categorical Data

Nonparametric Statistics

Statistical Quality Control

Decision Analysis

Filters

If x is a normal random variable with mean ( $\mu$ )equal to 80 and a standard deviation ( $\sigma$ )of 5, the z score for x = 88 is ___.

If x is uniformly distributed over the interval 8 to 12, inclusively (8 $\le$ x $\le$ 12), then the probability, P(9 $\le$ x $\le$ 11), is ___.

If x, the time (in minutes)to complete an oil change job at a certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 $\le$ x $\le$ 30), then the standard deviation of this distribution is ___.

If x is uniformly distributed over the interval 8 to 12, inclusively (8 $\le$ x $\le$ 12), then P(x < 7)is ___.