sample variance

If the degrees of freedom of the numerator is 15 and that of the denominator is 24 for testing the variances of two populations using F-test, then find the test value and the critical value at 95% confidence. The sample variances are 45 and 78. => 2.65, 1.83 or 1.73, 2..

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..

Find the sample variance and standard deviation for the normal daily high temperatures (in °F) in April for a sample of 7 cities as shown. 29, 50, 37, 61, 38, 34 and 47 => 120.6, 10.98 or 43, 6.55 or 103.3, 10.1 or 2157.3, 46.4..

A random sample of 81 students was tested for the problem solving approach skills. The variance of the scores obtained from the sample was found to be 144. Find the 80% confidence interval for the variance and standard deviation. Assume that the variable is n..

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..

In a random sample of 25 trees, the variance in height was found to be 6.9. Find the 95% confidence interval for the standard deviation. Assume that the variable is normally distributed. => between 4.9 and 13.7 or between 4.2 and 13.4 or between 5.5 and 14.1 or between 5.5 and 1..

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 sample variance and standard deviation for the amount of annual chocolate sales (in billion dollars) for a sample of seven countries in the world. 2.0, 4.9, 6.5, 2.1, 5.1, 3.2, 16.6 => 25.55, 5.06 or 386.48, 19.66 or 19.07, 4.37 or 21.9, 4.68..

The amount of car sales (in million dollars) in a country for 6 years is shown. Find the sample variance and standard deviation. 11.2, 11.9, 12.0, 12.8, 13.4, 14.3 => 958.94, 30.96 or 1.06, 1.03 or 1.28, 1.13 or 1.28, 1.64..

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..