] 1) The mean weight gain, after the change in diet for the laboratory animals, is at least 10 oz.

Ho:d	? < = > 10 oz
Ha:d	? < = > 10 oz

The mean difference in the home reassessments from the two town assessors was no more than $200.

Ho:d	? < = > $200
Ha:d	? < = > $200

2) Find the 90% confidence interval for estimating _d based on these paired data and assuming normality. (Give your answers correct to one decimal place.) Upper limit________ Lower limit

Before	63	44	56	47	48	70
After	53	30	47	57	59	43

3)An experiment was designed to estimate the mean difference in weight gain for pigs fed ration A as compared with those fed ration B. Eight pairs of pigs were used. The pigs within each pair were litter-mates. The rations were assigned at random to the two animals within each pair. The gains (in pounds) after 45 days are shown in the following table. Assuming weight gain is normal, find the 90% confidence interval estimate for the mean of the differences _d, where d = ration A - ration B. (Give your answers correct to two decimal places.) Upper Limit_____ Lower Limit______

Litter	1	2	3	4	5	6	7	8
Ration A	53	56	54	43	40	47	51	58
Ration B	49	48	52	35	39	38	44	56

4) The corrosive effects of various soils on coated and uncoated steel pipe was tested by using a dependent sampling plan. The data collected are summarized below, where d is the amount of corrosion on the coated portion subtracted from the amount of corrosion on the uncoated portion. Does this random sample provide sufficient reason to conclude that the coating is beneficial? Use = 0.01 and assume normality.n = 37, d = 214, d² = 6127 (a) Find t. (Give your answer correct to two decimal places.) (ii) Find the p-value. (Give your answer correct to four decimal places.)