Let x be the time seconds for a rat to complete maze Assume

Let x be the time seconds for a rat to complete maze. Assume that the distribution of x is normal. If the sample size n=13 the sample mean z=27.25 and the sample standard deviation s= 4.137, friend a 90% confidence interval for mu if possible. Let x be the time in seconds for a rat complete a . Assume that the distribution of x is highly . If the size n=13, the sample z =27.28, and the sample standard deviation a= 4.137, find a 90% confidence interval for mu if possible.

Solution

4) this is a small sample.n is < 30...n = 13.......and the distribution of x is highly skewed......

so, confidence interval = [ x-bar + or - t(alpha/2 , n-1) * s / sqrt(n) ]
= [ 27.28 - ( 1.782288 * 4.137 / sqrt(13) ) , 27.28 + ( 1.782288 * 4.137 / sqrt(13) ) ]
= [ 25.23501 , 29.32499 ]..............