variance of sample variance

The mean for the number of viewers of a sample of entertainment programs is 132, with a variance of 23. The mean for the number of advertisements of a sample of entertainment programs is 182, with a variance of 62. Compare the variations. => The number of vie..

The variance of the number of pages of a sample of 20 women's fitness magazines is 62 and the variance of the number of pages of a sample of 15 sports magazines is 23. At 90% confidence level, find the F-test value and check whether variances differ..

The variances corresponding to the number of students having attendence of 95% or above of a sample of 21 schools in one state and 16 schools of another are 20.3 and 9.8. Verify whether the variances for both the states differ at 80% and 90% confidence levels. => do no..

If X is a discrete random variable then variance of X denoted by V(X) is defined as V(X) = E [X - E(X)] 2 V(X) = E(X 2 ) - [E(X)] 2 ..

We have = n(n-1) p 2 (p+q) n - 2 + np = n 2 p 2 - np 2 + np = n 2 p 2 + np(1-p) = n 2 p 2 + npq Now V(x) = E(x 2 ) - [E(x)] 2 = n 2 p 2 + npq - n 2 p 2 = n..

In a statistical hypothesis test, s 2 is the sample variance, s 2 the population variance and n the sample size, than the formula for the chi-square test for a single variance is: => n s 2 σ 2 or ( n - 1 ) s 2 σ 2 or ( n - 1 ) σ 2 ..

Find the F-test value and the critical value at 95% confidence for testing the population variances. The data relating to samples are shown. Sample size Sample variance 30 12 25 8 => 1.2, 2.15 or 2.15, 1.2 or 1.94, 1.5 or 1.5, 1.94..

Find the F-test value for testing the difference between two population variances. The data shows the two samples from each of the populations. => 1.11 or 0.63 or 2.38 or 2.16..

A manufacturer of bulbs claims that the variance of the span of life of the bulbs is 320 hours. The inspection department selected a random sample of 15 bulbs and found the variance as 210 hours. Find the chi-square test value. At α = 0.05, is there enough eviden..

The formula for the confidence interval for a variance is _________ . => IV. or II. or III. or I...