Answer:
a) point estimate of the proportion of items returned for the population of sales transactions at the store in the given city
Point estimate = 0.3
b) The 95% confidence interval for the proportion of returns at the store in the given city
( 0.19958,0.40042)
Step-by-step explanation:
Given the Population proportion 'P'= 16% = 0.16
Given data a department store in a certain city sampled 80 items sold in January and found that 24 of the items were returned
The sample proportion
here x =24 and n = 80
The sample proportion
a)<u> Point estimate</u>:-
A point estimate of the true proportion P
Point estimate =
point estimate of the proportion of items returned for the population of sales transactions at the store in the given city
b) <u>The 95% confidence interval for the proportion </u>
The 95% confidence interval for the proportion of returns at the store in the given city
substitute all values we get ,
on simplification, we get
(0.3-0.10042 ,0.3+0.10042)
( 0.19958,0.40042)
<u>Conclusion</u>:-
a) point estimate of the proportion of items returned for the population of sales transactions at the store in the given city
Point estimate = 0.3
b) The 95% confidence interval for the proportion of returns at the store in the given city
( 0.19958,0.40042)