Question

what id a confidence interval

Answer 1

Solution :

The confidence interval is a interval estimate of a population parameter. A confidence interval is a range of values within which we expect that the value of the population parameter lie with some confidence. Since, this is a inferential procedure, therefore this is obtained by using the sample data. The higher the confidence level and higher the sample size the higher will be the reliability of our estimate. A confidence interval has generally three components, which are as follows :

i) Point estimate of the population parameter

ii) Standard error of the point estimate

(iii) Critical value of the sampling distribution

When we multiply the critical value and standard error, the obtained term is known as margin of error. The confidence interval has following general form :

(Point estimate ± critical value × standard error)