Question

Question 2: Please write 2 different questions and their answers about Confidence Intervals.

Question 3: Please give a brief explanation how you use statistics in your studied field.

Answer 1

Question 2:

1:

The Covid-19 pandemic has forced most governments to make it mandatory for certain employees to work from home. The impact of this work from home order depends on several factors such as the availability of internet service and the number of home computers in each household.

The Human Resources Department for the ABC Company is interested in determining the percentage of all employees from the company that has more than one home computer. In a survey of 492 employees, 27% indicated that they own more than one home computer. Develop a 90% confidence interval for the proportion of all ABC Company employees with more than one home computer.

Given information:

• The number of sampled employees (n) is 492.
• The estimated proportion of employees own more than one home computer (^p) is 0.27.

• Since the confidence level is 0.90, so it implies that the level of significance (α) is 0.10.

By using the standard normal table, the two-sided critical value obtained at 0.10 level of significance is +/- 1.645.

The 90% confidence interval for the proportion of all ABC Company employees with more than one home computer can be calculated as,

=0.27 ± 0.0329

= (0.2371,0.3029)

Therefore, the 90% confidence interval for the proportion of all ABC Company employees with more than one home computer is (0.2371, 0.3029).

2:

The First National Bank of Wilson has 650 checking account customers. A recent sample of 50 of these customers showed 26 have a Visa card with the bank.

Construct the 99% confidence interval for the proportion of checking account customers who have a Visa card with the bank.

Given Information

The total number of account customers in the First National Bank of Wilson.

50 of these customers showed 26 have a Visa card with the bank.

The 99% confidence interval will be:

= p ± z*(√p(1-p)/n)

= (0.338, 0.702)