Question

It is known that the mean of electricity consumption in a certain province is 721 kWh.

A technology company in the region thinks half of its employees consume more than the provincial mean. So it collects data from 15 employees randomly chosen and obtains the following data:

710           774           814           768           823

732           675           755           770           660

654           757           736           677           797

If the distribution of the monthly consumption of electrical energy is normal:

a) Is there evidence to say that the mean consumption of the electrical energy of the employees is superior tho the provincial mean?

b) What is the P-value of the decision?

Answer 1