5 IBM Survey The computer giant IBM has 329373 employees and

5. IBM Survey The computer giant IBM has 329,373 employees and 637,133 stockholders. A

vice president plans to conduct a survey to study the numbers of shares held by individual

stockholders.

a. Are the numbers of shares held by stockholders discrete or continuous?

b. Identify the level of measurement (nominal, ordinal, interval, ratio) for the numbers of

shares held by stockholders.

c. If the survey is conducted by telephoning 20 randomly selected stockholders in each of

the 50 United States, what type of sampling (random, systematic, convenience, stratified,

cluster) is being used?

d. If a sample of 1000 stockholders is obtained, and the average (mean) number of shares is

calculated for this sample, is the result a statistic or a parameter?

e. What is wrong with gauging stockholder views about employee benefits by mailing a ques-

tionnaire that IBM stockholders could complete and mail back?

Solution

a. Are the numbers of shares held by stockholders discrete or continuous?

Ans: Number of stockholders is discrete not continuos. Because number of stockholder cannot be 10.5 or 3009.90. It should be an integer number.

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b. Identify the level of measurement (nominal, ordinal, interval, ratio) for the numbers of shares held by stockholders.

Ans: A ratio variable is an interval variable only with one difference, ratio variable has a clear definition of 0. Stockholder can have zero number of shares. So level of measrument is ratio.

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c. If the survey is conducted by telephoning 20 randomly selected stockholders in each of the 50 United States, what type of sampling (random, systematic, convenience, stratified, cluster) is being used?

Ans: here the stockhoders were selected randomly from each states. States were not selected randomly. So it is not cluster sampling. It is startified sampling.

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d. If a sample of 1000 stockholders is obtained, and the average (mean) number of shares is calculated for this sample, is the result a statistic or a parameter?

Ans: Since the mean number of shares is calculated for sample not for population so it is a statitics.

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(d) What is wrong with gauging stockholder views about employee benefits by mailing a questionnaire that IBM stockholders could complete and mail back?

Ans: The questionnaire will be optional. All stock holders who receive the questionnaire not necessarily would be able to properly fill the form. And return the questionnaire resulting in a wrong conclusion.