In a sampling application to determine the average age of employees in management positions,the sample estimate was 50 years,reliability was 80 percent,and precision was 10 years.Which of the following would most likely result from an increase in the desired level of reliability to 90 percent?
A)The sample estimate would increase to 55 years.
B)The precision interval would be 40 to 60 years.
C)The precision interval would be 35 to 65 years.
D)The precision interval would have a lower probability of including the true (unknown)population average.

Question

Quizplus · Accepted Answer

Increasing the desired level of reliability to 90 percent would require a larger sample size, which in turn would decrease the precision interval. This means that the new precision interval would be wider, and therefore cover a larger range of ages. Based on the given information, the precision interval is currently 40 to 60 years (10 years of precision around the sample estimate of 50 years). Increasing the reliability to 90 percent would likely result in a new precision interval of 35 to 65 years. This is because the precision of 10 years needs to be maintained, but the reliability needs to be increased, requiring a larger sample size and wider interval. The sample estimate may or may not change, depending on the actual distribution of ages in the population, so it is not possible to determine this from the given information. Therefore, options A and D are unlikely. Option B is incorrect because a precision interval of 40 to 60 years is already given, so it does not reflect the impact of increasing reliability.

In a Sampling Application to Determine the Average Age of Employees