Exam 7: Sampling Distributions

Instruction 7-4 According to a survey,only 15% of customers who visited the web site of a major retail store made a purchase.Random samples of size 50 are selected. -Referring to Instruction 7-4,what proportion of the samples will have between 20% and 30% of customers who will make a purchase after visiting the web site?

Instruction 7-5 The manager of the customer service division of a major consumer electronics company is interested in determining whether the customers who have purchased a DVD player made by the company over the past 12 months are satisfied with their products. -Referring to Instruction 7-5,if there are 4 different brands of DVD players made by the company,the best sampling strategy would be to use a

Instruction 7-7 Online customer service is a key element to successful online retailing.According to a marketing survey,37.5% of online customers take advantage of the online customer service.Random samples of 200 customers are selected. -Referring to Instruction 7-7,the population mean of all possible sample proportions is ________.

Instruction 7-7 Online customer service is a key element to successful online retailing.According to a marketing survey,37.5% of online customers take advantage of the online customer service.Random samples of 200 customers are selected. -Referring to Instruction 7-7,90% of the samples proportions symmetrically around the population proportion will have between ________% and ________% of the customers who take advantage of online customer service.

The fact that the sample means are less variable than the population data can be observed from the standard error of the mean.

An electronic appliance chain gathered customer opinions on their services using the customer feedback forms that are attached to the product registration forms.This is an example of a convenience sample.

Which of the following can be reduced by proper interviewer training?

Using different frames to generate data can lead to totally different conclusions.

Which of the following is a result of failure to collect data on all items in the sample?

Instruction 7-2 The mean selling price of new homes in a country town over a year was $115,000.The population standard deviation was $25,000.A random sample of 100 new home sales from this town was taken. -Referring to Instruction 7-2,without doing the calculations,state in which of the following ranges the sample mean selling price is most likely to lie?

Instruction 7-6 According to an article,19% of the entire Australian population have high-speed access to the Internet.Random samples of size 200 are selected from the Australian population. -Referring to Instruction 7-6,among all the random samples of size 200,________% will have between 14% and 24% who have high-speed access to the Internet.

Instruction 7-5 The manager of the customer service division of a major consumer electronics company is interested in determining whether the customers who have purchased a DVD player made by the company over the past 12 months are satisfied with their products. -Referring to Instruction 7-5,which of the following methods of collecting data is NOT likely to produce a higher response rate?

In a ________ sample,items or individuals are selected without knowing their probabilities of selection.

A sample that does not provide a good representation of the population from which it was collected is referred to as a(n)________ sample.

If the amount of petrol purchased per car at a large petrol station has a population mean of $15 and a population standard deviation of $4 and it is assumed that the amount of petrol purchased per car is symmetric,there is approximately a 68.26% chance that a random sample of 16 cars will have a sample mean between $14 and $16.

A sampling distribution is defined as the probability distribution of possible sample sizes that can be observed from a given population.

A manufacturer of power tools claims that the average amount of time required to assemble their top-of-the-line table saw is 80 minutes with a standard deviation of 40 minutes.Suppose a random sample of 64 purchasers of this table saw is taken.The probability that the sample mean will be between 77 and 89 minutes is ________.

Instruction 7-6 According to an article,19% of the entire Australian population have high-speed access to the Internet.Random samples of size 200 are selected from the Australian population. -Referring to Instruction 7-6,the population mean of all the sample proportions is ________.

Which of the following sampling methods will more likely be susceptible to ethical violation?

There can be only one sample drawn from a population.