Question 1

A statistics class is composed of 60 percent females.If 15 students are selected randomly,what is the probability that this group will include either 8,9,10,or 11 females? Use the normal distribution.

Accepted Answer

The answer of A statistics class is composed of 60...

Question 2

A manufacturer of washing machines has experienced a 2% repair rate.In a city where 120,000 of its machines are located,the company plans to open its own repair service and needs to determine the number of repair workers to hire.Each worker can handle calls for 1000 machine repairs.If the company wants to cover calls 90% of the time,how many workers must it hire for the new repair facility?

Accepted Answer

The answer of A manufacturer of washing machines has experienced...

Question 3

Women make up 58% of the U.S.civilian workforce of 124 million.The U.S.Department of Commerce randomly selects 100 workers for a conference on national health care.What is the probability that more than 20 of these workers are female?

Accepted Answer

The answer of Women make up 58% of the U.S.civilian...

Question 4

An elementary school teacher learned that 40 percent of school age children have at least 3 cavities.The teacher has 30 students in his class.What is the standard deviation for the number of school age children that have at least 3 cavities?

Accepted Answer

The answer of An elementary school teacher learned that 40...

Question 5

An efficiency expert makes periodic checks for weighting errors for a long distance shipping firm.The expert inspects for errors in weighing,in recording weights,and errors in processing the bills of lading.Based on past records,the number of weekly errors for all shipments averages 5.30 with a standard deviation of 1.23,and the frequency histogram approximates a normal distribution.Suppose x is the number of weighing errors that will occur next week.
Compute the approximate probability for (4 ≤ x ≤ 7).

Accepted Answer

The answer of An efficiency expert makes periodic checks for...

Question 6

The selling price of various homes in a community follows the normal distribution with a mean of $176,000 and a standard deviation of $22,300.What is the probability that the next house will sell for less than $190,000?

Accepted Answer

The answer of The selling price of various homes in...

Question 7

An efficiency expert makes periodic checks for weighting errors for a long distance shipping firm.The expert inspects for errors in weighing,in recording weights,and errors in processing the bills of lading.Based on past records,the number of weekly errors for all shipments averages 5.30 with a standard deviation of 1.23,and the frequency histogram approximates a normal distribution.Suppose x is the number of weighing errors that will occur next week.Compute the approximate probability for (x = 6).

Accepted Answer

The answer of An efficiency expert makes periodic checks for...

Question 8

The recent average starting salary for new college graduates in computer information systems is $47,500.Assume salaries are normally distributed with a standard deviation of $4,500.What is the probability of a new graduate receiving a salary between $45,000 and $50,000?

Accepted Answer

The answer of The recent average starting salary for new...

Question 9

Let x be a binomial random variable.Find P(x ≥ 40)if n = 100 and $\pi$ = 0.32.

Accepted Answer

The answer of Let x be a binomial random variable.Find...

Question 10

A coin is flipped 14 times.Using the normal distribution,calculate the probability of observing either 4,5,or 6 heads.

Accepted Answer

The answer of A coin is flipped 14 times.Using the...

Question 11

Women make up 58% of the U.S.civilian workforce of 124 million.The U.S.Department of Commerce randomly selects 100 workers for a conference on national health care.If there are fewer than 45 or more than 65 females invited,severe political ramifications are possible.What is the probability that the conference planners will be criticized for the representation by women at the conference?

Accepted Answer

The answer of Women make up 58% of the U.S.civilian...

Question 12

In a paper mill,which produces newsprint from Southern Pine,the production manager finds a flaw for each 1000 feet of newsprint.He knows that the outcome is a Poisson process with a continuous distribution.If x = feet between flaws,what is the probability of finding 600 or more feet between the next two flaws?

Accepted Answer

The answer of In a paper mill,which produces newsprint from...

Question 13

In 1997,private planes had 1.5 fatal crashes per 100 thousand flying hours.For a continuous random variable with an exponential distribution: What is the probability that the time between the next two crashes will fall between 50 and 70 thousands hours,i.e.P(50 ≤ x ≤ 70); x = thousands of flying hours between fatal crashes.

Accepted Answer

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

Question 14

An elementary school teacher learned that 40 percent of school age children have at least 3 cavities.The teacher has 30 students in his class.How many students would he expect in his class to have at least three cavities?

Accepted Answer

The answer of An elementary school teacher learned that 40...

Question 15

In a paper mill,which produces newsprint from Southern Pine,the production manager finds a flaw for each 1000 feet of newsprint.He knows that the outcome is a Poisson process with a continuous distribution.A group of visitors is touring the plant.After arriving at the final stage of production,if they remain long enough to observe 330 feet of newsprint produced,what is the probability that they will miss seeing the next defect?

Accepted Answer

The answer of In a paper mill,which produces newsprint from...

Question 16

An elementary school teacher learned that 40 percent of school age children have at least 3 cavities.The teacher has 30 students in his class.What is the probability that 10 students from this class have at least 3 cavities?

Accepted Answer

The answer of An elementary school teacher learned that 40...

Question 17

The selling price of various homes in a community follows the normal distribution with a mean of $176,000 and a standard deviation of $22,300.What is the probability that the next house will sell for less than $158,000?

Accepted Answer

The answer of The selling price of various homes in...

Question 18

The selling price of various homes in a community follows the normal distribution with a mean of $176,000 and a standard deviation of $22,300.What is the probability that the next house will sell for between $150,000 and $168,000?

Accepted Answer

The answer of The selling price of various homes in...

Question 19

An efficiency expert makes periodic checks for weighting errors for a long distance shipping firm.The expert inspects for errors in weighing,in recording weights,and errors in processing the bills of lading.Based on past records,the number of weekly errors for all shipments averages 5.30 with a standard deviation of 1.23,and the frequency histogram approximates a normal distribution.Suppose x is the number of weighing errors that will occur next week.
Compute the approximate probability for (x ≤ 2).

Accepted Answer

The answer of An efficiency expert makes periodic checks for...

Question 20

Suppose that x is a binomial random variable with n = 100 and $\pi$ = 0.18.Employ the normal approximation to find P(15 ≤ x ≤ 21).

Accepted Answer

The answer of Suppose that x is a binomial random...

Quiz 7: Continuous Probability Distributions

A statistics class is composed of 60 percent females.If 15 students are selected randomly,what is the probability that this group will include either 8,9,10,or 11 females? Use the normal distribution.

Women make up 58% of the U.S.civilian workforce of 124 million.The U.S.Department of Commerce randomly selects 100 workers for a conference on national health care.What is the probability that more than 20 of these workers are female?

An elementary school teacher learned that 40 percent of school age children have at least 3 cavities.The teacher has 30 students in his class.What is the standard deviation for the number of school age children that have at least 3 cavities?

The selling price of various homes in a community follows the normal distribution with a mean of $176,000 and a standard deviation of $22,300.What is the probability that the next house will sell for less than $190,000?

The recent average starting salary for new college graduates in computer information systems is $47,500.Assume salaries are normally distributed with a standard deviation of $4,500.What is the probability of a new graduate receiving a salary between $45,000 and $50,000?

Let x be a binomial random variable.Find P(x ≥ 40)if n = 100 and π\piπ = 0.32.

A coin is flipped 14 times.Using the normal distribution,calculate the probability of observing either 4,5,or 6 heads.

An elementary school teacher learned that 40 percent of school age children have at least 3 cavities.The teacher has 30 students in his class.How many students would he expect in his class to have at least three cavities?

An elementary school teacher learned that 40 percent of school age children have at least 3 cavities.The teacher has 30 students in his class.What is the probability that 10 students from this class have at least 3 cavities?

The selling price of various homes in a community follows the normal distribution with a mean of $176,000 and a standard deviation of $22,300.What is the probability that the next house will sell for less than $158,000?

The selling price of various homes in a community follows the normal distribution with a mean of $176,000 and a standard deviation of $22,300.What is the probability that the next house will sell for between $150,000 and $168,000?

Suppose that x is a binomial random variable with n = 100 and π\piπ = 0.18.Employ the normal approximation to find P(15 ≤ x ≤ 21).

Let x be a binomial random variable.Find P(x ≥ 40)if n = 100 and $\pi$ = 0.32.

Suppose that x is a binomial random variable with n = 100 and $\pi$ = 0.18.Employ the normal approximation to find P(15 ≤ x ≤ 21).