Question

Confidence interval for one population parameter :

Question 1​​(3 marks)​

A UK government agency carries out a large-scale random survey of public attitudes towards the recession. 83 of the 500 workers surveyed indicated they were worried about losing their job. Calculate a 90% confidence interval of the population proportion of public attitudes? State any assumptions you used.

Answer 1

Solution:-

Given,

n=500, x=83, c=0.90

Therefore,

Z =Z = 1.645(from standard normal table)

90% confidence interval of the population proportion of public attitudes is,

90% confidence interval of the population proportion of public attitudes is (0.1386,0.1934).

Assumption:- Normal approximation can be used if

and .