sample mean formula

What formula is used to gain information about a sample mean when the variable is normally distributed or when the sample size is 30 or more? => z = X - μ σ or z = X ‾ - μ σ n or z = X ‾ - μ σ n or z = X - μ &sigm..

Which of the following is a property of sampling distribution? I. Mean of sampling distribution equals population mean. II. Sample mean comes closer to population mean than any other unbiased mean. III. As sample..

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 betwe..

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 of the resulting h..

The number of ATM transactions of a bank per day were recorded at 12 locations in a city. The mean of the sample was 88.5 transactions, with a sample standard deviation of 42. Find the 98% confidence interval of the true mean. => 19.06 < μ < 157.94 o..

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. Find the 95% confidence interval. => The interval is between 97.75 and 102.25 or The interval is between 1.15 and 100 or The interv..

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 ≠ ..

Select the correct statement(s). I. Increase in sample size will make the confidence interval of the population mean wider. II. A 90% confidence interval will be wider than a 99% confidence interval. III. Sample mean can never be the same as population m..

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. => 15.52%..

Not all atoms of a given sample disintegrate together. Some atoms disintegrate right in the beginning for which the lifetime is zero. Therefore the lifetime of atoms, which disintegrate in between, ranges from zero to infinity...