Question

Soru 10. The mean and standard deviation of a sample of 400 are calculated as 40 and 6, respectively. What will be the confidence level if the limits of interval are 37 and 43?

Answer 1

So here

n = 400 , T = 40,s= 6

100(1-$\alpha$) % confidence interval is given by :

t1-a/2 X- = 40 + ti-a/2 - 400 = 40 + 11-a/2 X 0.3

So from the given values, 43 and 37 , we find that :

t1-a/2 X 0.3=3 = t1-a/2 = 10

df = 399

Now using calculators we find that t values takes the score of 10 at 100% confidence level or 0 significance level.

So, if the given limits are true, then confidence level should be 100%