Question
Pig farmers in Shaktoolik, Alaska are trying to sell pork as the “other white meat besides chicken” (according to the Shaktoolik News), claiming to evolved a leaner more efficient breed of pig. One of the claimed advantages of this new breed of pig is that it takes substantially less time for a pig to reach the final market weight (thus saving the farmer money in feeding and tending). Based on a national standard the average pig usually takes 160 days of breeding time with a standard deviation of 40 days. The agricultural researchers from the University of the North randomly selected 81 new breed pigs and determined their average breeding days to be 170 days. At a twenty significance level test the claim that the new breed of Shaktoolik pigs have the same breeding time . Assume the population standard deviation is known.
1. Nordstrom is a leading retailer of woman’s clothing is planning to open a new store in Scammon Bay, Alaska. To minimize its start up cost Nordstrom not to stock suits for the tallest 10 percent and the shortest 20% of the woman. Find the minimum and maximum heights of the woman suits to be stocked. Woman normally distributed heights with a mean of 56 inches and a standard deviation of
17 inches.
Question
1 . In Alaska, a random sample of 15 eight-grade students has a mean score of 265 with a sample standard deviation of 55 on a national mathematical assessment test. This prompts a state school administrator to declare that the mean score is more than 260. At a five percent significance level, is there enough evidence to support the administrator’s claim? Assume the population standard deviation is unknown; use the “t” procedure. (6 points)
2 . In a simple random sample of 42 Alaskan civil engineering firms the mean number of employees is sixteen. The population standard deviation is estimated to be four employees. Establish the 95.5% confidence interval for the population mean. Assume the population standard deviation is known; use the “z” procedure. (5 points)