A sample of size 65 gave a mean 7.4 and standard deviation as 1.6 then 95% confidence interval for population mean will be Select one: O (17.008, 17.792) O 127.008, 30.008) O 17.008, 7.7921 O (9,265, 10.735)

23) The records of 100 postal employees who volunteered for a study, showed that the average time these employees had worked for the postal service was x = standard deviation of the population of time postal service employees have spent with the postal service is approximately 8 years. Assume that we know that the normal with standard deviation o 5 years. A 95% confidence interval for the mean time u the population of postal service employees have spent with the postal service is:

Determine the sample size required to estimate a population mean to within 11 units given that the population standard deviation is 50. Use a confidence level of 95%. Sample Size =

The ages of a group of 134 randomly selected adult females have a standard deviation of 18.2 years. Assume that the ages of female statistics students have less variation than ages of females in the general population, so let o = 18.2 years for the sample size calculation. How many female statistics student ages must be obtained in order to estimate the mean age of all female statistics students? Assume that we want 98% confidence that the sample mean is within one-half year of the population mean. Does it seem reasonable to assume that the ages of female statistics students have less variation than ages of females in the general population? The required sample size is 7194 . (Round up to the nearest whole number as needed.) Does it seem reasonable to assume that the ages of female statistics students have less variation than ages of females in the general population? A. No, because there is no age difference between the population of statistics students and the general population. B.…

Dr. Higney, an academic researcher in an English department, wants to learn about the average length of a novel. In order to do this, Dr. Higney collects data on the word counts of 200 randomly selected novels. The sample mean of this data set is = 85252 with a sample standard deviation of 8413 words. Using this data, construct a 90% confidence interval for the true mean length of novels. (84,273.50, 86,230.51) (82719.67,89784.33) (94086.04, 96417.96) (80937.53, 90566.47) S

The ages of a group of 134 randomly selected adult females have a standard deviation of 18.2 years. Assume that the ages of female statistics students have less variation than ages of females in the general population, so let o = 18.2 years for the sample size calculation. How many female statistics student ages must be obtained in order to estimate the mean age of all female statistics students? Assume that we want 98% confidence that the sample mean is within one-half year of the population mean. Does it seem reasonable to assume that the ages of female statistics students have less variation than ages of females in the general population? The required sample size is. (Round up to the nearest whole number as needed.)

The ages of a group of 138 randomly selected adult females have a standard deviation of 16.1 years. Assume that the ages of female statistics students have less variation than ages of females in the general population, so let o = 16.1 years for the sample size calculation. How many female statistics student ages must be obtained in order to estimate the mean age of all female statistics students? Assume that we want 99% confidence that the sample mean is within one-half year of the population mean. Does it seem reasonable to assume that the ages of female statistics students have less variation than ages of females in the general population? The required sample size is (Round up to the nearest whole number as needed.) Does it seem reasonable to assume that the ages of female statistics students have less variation than ages of females in the general population? O A. Yes, because statistics students are typically younger than people in the general population. OB. No, because statistics…

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