The data represent a sample of the number of home fires started by candles for the past several years. (Data are from the National Fire Protection Association.) Find the 99% confidence interval for the mean number of home fires started by candles each year. Round your answer to one decimal place. (You are allowed to use a class calculator or graphing calculator to find the mean and standard deviation.) 5460   5900   6090   6310   7160   8440

DATAfile: Costco You may need to use the appropriate technology to answer this question. Consumer Reports uses a 100-point customer satisfaction score to rate the nation's major chain stores. Assume that from past experience with the satisfaction rating score, a population standard deviation of ? = 13 is expected. In 2012, Costco, with its 432 warehouses in 40 states, was the only chain store to earn an outstanding rating for overall quality. A sample of 15 Costco customer satisfaction scores follows. 95 90 83 75 95 98 80 83 82 93 86 80 94 64 62 (a) What is the sample mean customer satisfaction score for Costco?   (b) What is the sample variance? (Round your answer to two decimal places.)   (c) What is the sample standard deviation? (Round your answer to two decimal places.)   (d) Construct a hypothesis test to determine whether the population standard deviation of ? = 13 should be rejected for Costco. With a 0.05 level of significance, what is your conclusion?…

Every year, the students at a school are given a musical aptitude test that rates them from 0 (no musical aptitude) to 5 (high musical aptitude). This year's results are given in the frequency distribution:   Aptitude Score 0 1 2 3 4 5 Frequency 1 6 4 1 5 2   Calculate the sample standard deviation of this data. Answer using two decimal places.

A random sample of a population of size n = 36, find the prob that the mean is between 110 and 115. The pop u is 100, and the sd is 15.