A population has a standard deviation of 8. What is the minimum sample size needed to estimate a mean to within 2 units with 66.8% confidence? O A. 13 О В. 15 ОС. 12 O D. 16 O E. 14

5.4.18-T Question Help The population mean and standard deviation are given below. Find the indicated probability and determine whether a sample mean in the given range below would be considered unusual. If convenient, use technology to find the probability. For a sample of n= 38, find the probability of a sample mean being less than 12,748 or greater than 12,751 when p= 12,748 and o= 2.4. For the given sample, the probability of a sample mean being less than 12,748 or greater than 12,751 is (Round to four decimal places as needed.) Enter your answer in the anower box and then click Check Answer. part 1emaining Clear All ..I12:54 hp -> esc & *- backspace #3 6. 3. 4 У e tab en d. 00

2. The average number of customers that visited a particular store during the past year is 160 per day and a standard deviation of 25 customers per day. A random sample of 64 days is chosen from this population. The standard deviation of the sample mean equals: a. 12.649. b. 25.0. c. 2.56. d. 3.125. е. 8.0

The mass of a species of mouse commonly found in houses is normally distributed with a mean of 21 grams with a standard deviation of 0.15 grams. Round your answers to 2 decimals. b) 10% of all mice have a mass of more than _____ grams.