Question: Question 2:

Answer the following questions by putting well in evidence your progress.

a) A company tries to introduce a new product on a market about 3 millions of consumers. A marketing research reveals that on a random sample of 3000 persons interrogated, 1400 individuals would be possible users. Which is the reliable interval associated to the estimation of the proportion of the possible consumers for this new product, with a level of 95 % confidence?

b) By considering the statement and the result of b), between which limits can be situated the number of units of the product which the company can hope to sell on this market?

c) A responsible in training in a company prepared a test to measure the degree of skill of the employees during the execution of a certain task. For a random sample of 12 employees, we obtained the following results in the test in question:

67 74 68 71

77 73 67 79

62 76 65 81

Supposing that the results of the test are normally distributed, estimate the average result

from all the employees with a level of 99 % confidence.

c) A responsible in training in a company prepared a test to measure the degree of skill of the employees during the execution of a certain task. For a random sample of 12 employees, we obtained the following results in the test in question:

67 74 68 71

77 73 67 79

62 76 65 81

Supposing that the results of the test are normally distributed, estimate the average result

from all the employees with a level of 99 % confidence.