overall sample mean

A central office operator has observed that the long distance telephone calls are normally distributed with a mean of 6 minutes and a standard deviation of 2 minutes. If random samples of 32 calls were selected, what is the probability that the length of the sample ..

A random sample of 86 days taken at a large hospital shows that an average of 32 patients were treated per day. The 95% confidence interval of the mean number of patients treated each day at the hospital is between 30 and 34. Find the 95% confidence interval of the mean..

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. Test at the 0.05 level of confidence and state whether or not to accept the null hypothesis. => The null hypothesis is accepted or ..

A sample of scores of 250 candidates has a mean of 47.2 with a standard deviation of 18.6. Find 90% and 95% confidence interval of the population mean and determine which is larger? => (45.3, 49.1) and (44.9, 49.5) and 95% or (45.26, 49.14) and (44.89, 49.51) and 90% o..

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...

Select the correct statement(s). I. A point estimate is a specific numerical value estimate of a parameter. II. The sample mean is a better estimator of the population mean than the sample median or sample mode. III. Of all the statistics that can b..

The average protein content in different types of nuts is 20 g, and the standard deviation is 5 g. Assume the variable is normally distributed. If a sample of 16 nuts are selected, then find the probability that the mean of the sample will be greater than 22 g. => 65.5..

The average annual temperature of a place is 68°F and the standard deviation is 10°F. If a random sample of 36 days is taken, then find the probability that the mean sample temperature is less than 70°F? => 89.62% or 39.62% or 10.38% or 60.38%..

The 95% confidence interval for the mean number of tablets in a bottle of calcium tablets is between 149.04 and 150.96. The standard deviation is 3 tablets. Find the size of the random sample that was used to determine this interval. => 40 or 38 or 6 or 150..

The 95% confidence interval for the mean weight of a sack of potatoes is between 4.92 and 5.08. If a random sample of 32 sacks was used to determine this interval, what was the standard deviation? => 0.04 or 0.16 or 3.92 or 0.23..