sample variance and sample standard deviation

The amount of magazine sales (in million dollars) for a sample of 7 years are 2.6, 1.8, 2.0, 3.2, 1.6, 3.4, 2.3. Find the sample variance and sample standard deviation. => 1.066 and 1.136 or 0.475 and 0.689 or 1.136 and 1.066 or 2.113 and ..

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 th..

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...

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 ..

The university authorities wanted to estimate the average age of the students in their university by taking a random sample of 25 students. The standard deviation was found to be 3 years. Find the 95% confidence interval for the variance (σ 2 ) and ..

Select the incorrect statement(s). I. A sampling distribution of sample means is a distribution obtained by using the means computed from random samples of a specific size taken from a population. II. Sampling error is the difference between the sample..

Assume that the weights of 3,000 students at a university are normally distributed with mean 150 pounds and a standard deviation of 7 pounds. If 100 samples of 30 students each are obtained, then what would be the expected mean and standard deviation..

The mean score on a standardized test is 100 with a standard deviation of 8. A random sample of 48 scores was found to have a mean of 98. State the null hypothesis and alternative hypothesis. => H o : The mean score = 100, H a : The mean score ≠ 100 or H o..

In a NBA playoff season the average number of points scored in a game was 200. Assume the standard deviation was 75. If a random sample of 20 games is selected, then what is the probability that the mean of the sample is lesser than 220? => 17.20% or 33.80% o..

Average score of the students in a statistics contest is 65, and the standard deviation is 15. If a random sample of 16 students who participated in the contest are selected, then find the probability that the sample mean of the scores lies between 61 and 67...