Question 1

The probability of a success on any trial of a binomial experiment is 20%.Find the probability that the proportion of success in a sample of 400 is less than 18%.

Accepted Answer

The answer of The probability of a success on any...

Question 2

A trucking firm has trucks that average a payload of 22.5 tons and a standard deviation of 1.5 tons.An accounting firm is auditing the shipping orders for the past year for billing errors.It chooses a random sample of 64 shipping orders.What is the probability that the sample mean weight will be within 1 ton of the true population mean of 22.5 tons?

Accepted Answer

The answer of A trucking firm has trucks that average...

Question 3

In a production of 1000 plastic moldings,75 were incompletely formed and had to be discarded.Based on these data the total production of plastic moldings should have what estimated proportion of incompletely formed moldings?

Accepted Answer

The answer of In a production of 1000 plastic moldings,75...

Question 4

A population consisted of 500 cases involving shoplifters.If a random sample of 300 was taken and in 90 cases the offender was under age 18,in how many of the 500 cases would you say the person involved was under age 18?
____________________ cases

Accepted Answer

The answer of A population consisted of 500 cases involving...

Question 5

The chairman of a statistics department in a certain college believes that 70% of the department's graduate assistantships are given to international students.A random sample of 50 graduate assistants is taken.Assume that the chairman is correct and that $\pi$
 = 0.70.What is the probability that the sample proportion p will be between 0.65 and 0.73?

Accepted Answer

The answer of The chairman of a statistics department in...

Question 6

The amount of time spent by American adults playing sports per day is normally distributed with a mean of 4 hours and standard deviation of 1.25 hours.Find the probability that a randomly selected American adult plays sports for more than 5 hours per day.

Accepted Answer

The answer of The amount of time spent by American...

Question 7

A producer of a juice drink advertises that it contains 10% real fruit juices.A sample of 75 bottles of the drink is analyzed and the percent of real fruit juices is found to be 6.5%.If the true proportion is actually 0.10,what is the probability that the sample percent will be 6.5% or less?

Accepted Answer

The answer of A producer of a juice drink advertises...

Question 8

In an effort to identify the true proportion of shoplifters who are under age 18,a random sample of 300 shoplifting cases was taken.One hundred and twenty of those cases involved persons under age 18.What value would be used to estimate the true proportion of under age 18 shoplifters?

Accepted Answer

The answer of In an effort to identify the true...

Question 9

The publisher of a daily newspaper claims that 90% of its subscribers are under the age of 30.Suppose that a sample of 300 subscribers is selected at random.Assuming the claim is correct,approximate the probability of finding at least 240 subscribers in the sample under the age of 30.

Accepted Answer

The answer of The publisher of a daily newspaper claims...

Question 10

A manufacturer of printers claims that their color cartridge will print an average of 200 4-by-6 photos with a standard deviation of 60 photos.A random sample of 40 customers counted the number of photos printed with one cartridge.If the manufacturer's claim is correct,what is the probability that the average customer printed less than 195 pages with one cartridge?

Accepted Answer

The answer of A manufacturer of printers claims that their...

Question 11

The heights of men in the USA are normally distributed with a mean of 68 inches and a standard of 4 inches.A random sample of five men is selected.What is the probability that the sample mean is greater than 70 inches?

Accepted Answer

The answer of The heights of men in the USA...

Question 12

If young children watch an average of 105 minutes of TV per day with a standard deviation of 30 minutes per day,what is the probability that a random sample of 60 children will watch more than 110 minutes of TV per day?

Accepted Answer

The answer of If young children watch an average of...

Question 13

Suppose it is known that 60% of students at a particular college are smokers.A sample of 500 students from the college is selected at random.Approximate the probability that at least 280 of these students are smokers.

Accepted Answer

The answer of Suppose it is known that 60% of...

Question 14

The heights of men in the USA are normally distributed with a mean of 68 inches and a standard of 4 inches.What is the probability that a randomly selected man is taller than 70 inches?

Accepted Answer

The answer of The heights of men in the USA...

Question 15

A manufacturer of printers claims that their color cartridge will print an average of 200 4-by-6 photos with a standard deviation of 60 photos.A random sample of 40 customers counted the number of photos printed with one cartridge.If the manufacturer's claim is correct,what is the probability that the average customer printed at least 185 pages with one cartridge?

Accepted Answer

The answer of A manufacturer of printers claims that their...

Question 16

A videocassette rental store wants to know what proportion of its stock should include the Beta format VCR.A random sample of the owners of VCRs is suggested.Five hundred VCR owners are asked if they own the Beta or VHS format.Out of 500 interviewed,125 were owners of the Beta format.Presume that the true population proportion of Beta format VCRs is $\pi$
 = 0.32.What is the probability that the sample proportion p will be within 0.04 of the true proportion of Beta format ownership?

Accepted Answer

The answer of A videocassette rental store wants to know...

Question 17

A manufacturer of printers claims that their color cartridge will print an average of 200 4-by-6 photos with a standard deviation of 60 photos.A random sample of 40 customers counted the number of photos printed with one cartridge.If the manufacturer's claim is correct,what is the probability that the average customer printed between 190 and 205 pages with one cartridge?

Accepted Answer

The answer of A manufacturer of printers claims that their...

Question 18

The amount of time spent by American adults playing sports per day is normally distributed with a mean of 4 hours and standard deviation of 1.25 hours.Find the probability that if four American adults are randomly selected,their average number of hours spent playing sports is more than 5 hours per day.

Accepted Answer

The answer of The amount of time spent by American...

Question 19

The heights of men in the USA are normally distributed with a mean of 68 inches and a standard of 4 inches.What is the probability that the mean height of a random sample of 35 men is greater than 70 inches?

Accepted Answer

The answer of The heights of men in the USA...

Question 20

The Sunbelt City Peewee baseball organization has ordered 48 dozen balls from the Liteflite Company for use in its summer program.The company has guaranteed a 10% discount on the total cost if 32 or more of the balls are defective.Experience in the past has shown 5% defects.A sample of 50 balls will be taken,and the discount will be given if the sample proportion of defective balls is at least 32 in 48 dozen.What is the probability that the organization will get the 10% discount?

Accepted Answer

The answer of The Sunbelt City Peewee baseball organization has...

Quiz 8: Sampling Distributions

The probability of a success on any trial of a binomial experiment is 20%.Find the probability that the proportion of success in a sample of 400 is less than 18%.

In a production of 1000 plastic moldings,75 were incompletely formed and had to be discarded.Based on these data the total production of plastic moldings should have what estimated proportion of incompletely formed moldings?

A population consisted of 500 cases involving shoplifters.If a random sample of 300 was taken and in 90 cases the offender was under age 18,in how many of the 500 cases would you say the person involved was under age 18? ____________________ cases

The amount of time spent by American adults playing sports per day is normally distributed with a mean of 4 hours and standard deviation of 1.25 hours.Find the probability that a randomly selected American adult plays sports for more than 5 hours per day.

A producer of a juice drink advertises that it contains 10% real fruit juices.A sample of 75 bottles of the drink is analyzed and the percent of real fruit juices is found to be 6.5%.If the true proportion is actually 0.10,what is the probability that the sample percent will be 6.5% or less?

In an effort to identify the true proportion of shoplifters who are under age 18,a random sample of 300 shoplifting cases was taken.One hundred and twenty of those cases involved persons under age 18.What value would be used to estimate the true proportion of under age 18 shoplifters?

The publisher of a daily newspaper claims that 90% of its subscribers are under the age of 30.Suppose that a sample of 300 subscribers is selected at random.Assuming the claim is correct,approximate the probability of finding at least 240 subscribers in the sample under the age of 30.

The heights of men in the USA are normally distributed with a mean of 68 inches and a standard of 4 inches.A random sample of five men is selected.What is the probability that the sample mean is greater than 70 inches?

If young children watch an average of 105 minutes of TV per day with a standard deviation of 30 minutes per day,what is the probability that a random sample of 60 children will watch more than 110 minutes of TV per day?

Suppose it is known that 60% of students at a particular college are smokers.A sample of 500 students from the college is selected at random.Approximate the probability that at least 280 of these students are smokers.

The heights of men in the USA are normally distributed with a mean of 68 inches and a standard of 4 inches.What is the probability that a randomly selected man is taller than 70 inches?

The heights of men in the USA are normally distributed with a mean of 68 inches and a standard of 4 inches.What is the probability that the mean height of a random sample of 35 men is greater than 70 inches?