Question 1

Grades for a statistics exam for a certain class follow the normal probability distribution with a mean of 82 and a standard deviation of 12.What percentage of the students in the class earned a B grade (80-89)?

Accepted Answer

The answer of Grades for a statistics exam for a...

Question 2

The time it takes a technician to fix a computer problem is exponentially distributed with a mean of 15 minutes.What is the probability that it will take a technician between 10 to 15 minutes to fix a computer problem?

Accepted Answer

The answer of The time it takes a technician to...

Question 3

If x is a normal random variable with a mean of 100 and a standard deviation of 10,find the following probabilities:
A)P(x ≥ 128)
B)P(x ≤ 113)
C)P(87 ≤ x ≤ 98)

Accepted Answer

The answer of If x is a normal random variable...

Question 4

If z is a standard normal random variable,find the value z₁ for which: A)P(0 ≤ z ≤ z₁)= 0 .276 B)P(z ≥ z₁)= 0.341 C)P(z ≥ z₁)= 0.819 D)P(-z₁ ≤ Z ≤ z₁)= 0.785

Accepted Answer

The answer of If z is a standard normal random...

Question 5

The time it takes a technician to fix a computer problem is exponentially distributed with a mean of 15 minutes.What is the variance of the time it takes a technician to fix a computer problem?
____________________ minutes

Accepted Answer

The answer of The time it takes a technician to...

Question 6

If a computer statistical package were to simulate 500 random observations from a normal distribution with mean $\mu$ = 100 and standard deviation $\text { σ}$ = 50,what percentage of these observations would you expect to have a value of 200 or more? Do you think the actual number in the " ≥ 200" range would equal the expected number in this range? If so,why? If not,why not?

Accepted Answer

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Question 7

The binomial distribution is symmetrical whenever the population proportion $\pi$ is ____________________,and approaches symmetry for values that are close to ____________________.

Accepted Answer

The answer of The binomial distribution is symmetrical whenever the...

Question 8

In the normal distribution,the right half of the curve is a mirror image of the _________________________,since the distribution is ____________________.

Accepted Answer

The answer of In the normal distribution,the right half of...

Question 9

Grades for a statistics exam for a certain class follow the normal probability distribution with a mean of 82 and a standard deviation of 12.What percentage of the students in the class had a grade 81 or more?

Accepted Answer

The answer of Grades for a statistics exam for a...

Question 10

The time it takes a technician to fix a computer problem is exponentially distributed with a mean of 15 minutes.What is the probability that it will take a technician less than 10 minutes to fix a computer problem?

Accepted Answer

The answer of The time it takes a technician to...

Question 11

For a Poisson process,the ____________________ distribution describes the continuous random variable x,where x is the amount of time,space,or distance between occurrences of these rare events.

Accepted Answer

The answer of For a Poisson process,the ____________________ distribution describes...

Question 12

Grades for a statistics exam for a certain class follow the normal probability distribution with a mean of 82 and a standard deviation of 12.What percentage of the students in the class earned a C grade (70-79)?

Accepted Answer

The answer of Grades for a statistics exam for a...

Question 13

If we ____________________ the normal curve,we express the original x values in terms of their number of standard deviations away from the mean.

Accepted Answer

The answer of If we ____________________ the normal curve,we express...

Question 14

The total area beneath the curve of any continuous distribution is ____________________.

Accepted Answer

The answer of The total area beneath the curve of...

Question 15

In the normal distribution,the total area under the curve is equal to ____________________.

Accepted Answer

The answer of In the normal distribution,the total area under...

Question 16

In 1997,private planes had 1.5 fatal crashes per 100 thousand flying hours.Assume a continuous random variable with a exponential distribution.A national association of private plane owners has 560 members who fly 1.5 million miles each year.The mileage crash rate has been estimated to be 20 per 100 million miles of air travel.What is the probability that the next crash by a member of the association will not occur until more than one year from now?

Accepted Answer

The answer of In 1997,private planes had 1.5 fatal crashes...

Question 17

The probability that any continuous random variable x will take on any specific value along an interval is ____________________.

Accepted Answer

The answer of The probability that any continuous random variable...

Question 18

In 2000,the average charge of tax preparation was $95.Assuming a normal distribution and a standard deviation of $10,use the approximate areas beneath the normal curve,as discussed in this section,to answer: What proportion of tax preparation fees were exactly $100?

Accepted Answer

The answer of In 2000,the average charge of tax preparation...

Question 19

A manufacturer produces Walkman tap players/radios.The electronic components are positioned in the outer case after the case has been given an epoxy finish.The production manager must time the drying process with the total assembly line and therefore must determine the appropriate drying time.An intensive cost analysis indicated that a risk of just 0.3% of the cases being wet and therefore smudged was acceptable.If drying times are normally distributed with a mean of 3.6 minutes and a standard deviation of 0.6 minutes,what time setting should the production manager set for the automatic timer which controls the production line?
____________________ minutes

Accepted Answer

The answer of A manufacturer produces Walkman tap players/radios.The electronic...

Question 20

A computer statistical package has simulated 1000 random observations from a normal distribution with mean $\mu$ = 50 and standard deviation $\sigma$ = 10.Sketch the approximate box-and-whisker plot for the resulting data.

Accepted Answer

The answer of A computer statistical package has simulated 1000...

Quiz 7: Continuous Probability Distributions

Grades for a statistics exam for a certain class follow the normal probability distribution with a mean of 82 and a standard deviation of 12.What percentage of the students in the class earned a B grade (80-89)?

The time it takes a technician to fix a computer problem is exponentially distributed with a mean of 15 minutes.What is the probability that it will take a technician between 10 to 15 minutes to fix a computer problem?

If x is a normal random variable with a mean of 100 and a standard deviation of 10,find the following probabilities: A)P(x ≥ 128) B)P(x ≤ 113) C)P(87 ≤ x ≤ 98)

If z is a standard normal random variable,find the value z₁ for which: A)P(0 ≤ z ≤ z₁)= 0 .276 B)P(z ≥ z₁)= 0.341 C)P(z ≥ z₁)= 0.819 D)P(-z₁ ≤ Z ≤ z₁)= 0.785

The time it takes a technician to fix a computer problem is exponentially distributed with a mean of 15 minutes.What is the variance of the time it takes a technician to fix a computer problem? ____________________ minutes

The binomial distribution is symmetrical whenever the population proportion $\pi$ is ,and approaches symmetry for values that are close to .

In the normal distribution,the right half of the curve is a mirror image of the _____,since the distribution is .

Grades for a statistics exam for a certain class follow the normal probability distribution with a mean of 82 and a standard deviation of 12.What percentage of the students in the class had a grade 81 or more?

The time it takes a technician to fix a computer problem is exponentially distributed with a mean of 15 minutes.What is the probability that it will take a technician less than 10 minutes to fix a computer problem?

For a Poisson process,the ____________________ distribution describes the continuous random variable x,where x is the amount of time,space,or distance between occurrences of these rare events.

Grades for a statistics exam for a certain class follow the normal probability distribution with a mean of 82 and a standard deviation of 12.What percentage of the students in the class earned a C grade (70-79)?

If we ____________________ the normal curve,we express the original x values in terms of their number of standard deviations away from the mean.

The total area beneath the curve of any continuous distribution is ____________________.

In the normal distribution,the total area under the curve is equal to ____________________.

The probability that any continuous random variable x will take on any specific value along an interval is ____________________.

In 2000,the average charge of tax preparation was $95.Assuming a normal distribution and a standard deviation of $10,use the approximate areas beneath the normal curve,as discussed in this section,to answer: What proportion of tax preparation fees were exactly $100?

A computer statistical package has simulated 1000 random observations from a normal distribution with mean $\mu$ = 50 and standard deviation $\sigma$ = 10.Sketch the approximate box-and-whisker plot for the resulting data.

Quiz 7: Continuous Probability Distributions

Grades for a statistics exam for a certain class follow the normal probability distribution with a mean of 82 and a standard deviation of 12.What percentage of the students in the class earned a B grade (80-89)?

The time it takes a technician to fix a computer problem is exponentially distributed with a mean of 15 minutes.What is the probability that it will take a technician between 10 to 15 minutes to fix a computer problem?

If x is a normal random variable with a mean of 100 and a standard deviation of 10,find the following probabilities: A)P(x ≥ 128) B)P(x ≤ 113) C)P(87 ≤ x ≤ 98)

If z is a standard normal random variable,find the value z1 for which: A)P(0 ≤ z ≤ z1)= 0 .276 B)P(z ≥ z1)= 0.341 C)P(z ≥ z1)= 0.819 D)P(-z1 ≤ Z ≤ z1)= 0.785

The time it takes a technician to fix a computer problem is exponentially distributed with a mean of 15 minutes.What is the variance of the time it takes a technician to fix a computer problem? ____________________ minutes

The binomial distribution is symmetrical whenever the population proportion π\piπ is ____________________,and approaches symmetry for values that are close to ____________________.

In the normal distribution,the right half of the curve is a mirror image of the _________________________,since the distribution is ____________________.

Grades for a statistics exam for a certain class follow the normal probability distribution with a mean of 82 and a standard deviation of 12.What percentage of the students in the class had a grade 81 or more?

The time it takes a technician to fix a computer problem is exponentially distributed with a mean of 15 minutes.What is the probability that it will take a technician less than 10 minutes to fix a computer problem?

For a Poisson process,the ____________________ distribution describes the continuous random variable x,where x is the amount of time,space,or distance between occurrences of these rare events.

Grades for a statistics exam for a certain class follow the normal probability distribution with a mean of 82 and a standard deviation of 12.What percentage of the students in the class earned a C grade (70-79)?

If we ____________________ the normal curve,we express the original x values in terms of their number of standard deviations away from the mean.

The total area beneath the curve of any continuous distribution is ____________________.

In the normal distribution,the total area under the curve is equal to ____________________.

The probability that any continuous random variable x will take on any specific value along an interval is ____________________.

In 2000,the average charge of tax preparation was $95.Assuming a normal distribution and a standard deviation of $10,use the approximate areas beneath the normal curve,as discussed in this section,to answer: What proportion of tax preparation fees were exactly $100?

A computer statistical package has simulated 1000 random observations from a normal distribution with mean μ\muμ = 50 and standard deviation σ\sigmaσ = 10.Sketch the approximate box-and-whisker plot for the resulting data.

If z is a standard normal random variable,find the value z₁ for which: A)P(0 ≤ z ≤ z₁)= 0 .276 B)P(z ≥ z₁)= 0.341 C)P(z ≥ z₁)= 0.819 D)P(-z₁ ≤ Z ≤ z₁)= 0.785

The binomial distribution is symmetrical whenever the population proportion $\pi$ is ,and approaches symmetry for values that are close to .

In the normal distribution,the right half of the curve is a mirror image of the _____,since the distribution is .

A computer statistical package has simulated 1000 random observations from a normal distribution with mean $\mu$ = 50 and standard deviation $\sigma$ = 10.Sketch the approximate box-and-whisker plot for the resulting data.