Answer to Question #14281 in Statistics and Probability for Nita

Question

The following table shows return on equity (ROE) figures for 2007, for a sample of six companies listed on the Tel Aviv stock exchange

Company ROE
Bezeq 25.83
Clal Industrials 25.35
Harel Insurance 22.60
Koor Insurance 28.72
Mizrahi Bank 17.10
Strauss Group 15.40

1.1) Compute the sample variance and sample standard deviation for these data.
1.2) What is the 95 per cent confidence interval for the unknown population varience?
1.3) Test a claim that the unknown population varience is more than 24.