3. Find the critical value and the rejection region for a two-tailed test with = 0.08 Graph it, find the area in Z table that is closest to .5 & corresponding Z value.

4. The USDA reports that the mean cost of raising a child from birth to age 2 in a rural area is $8390. You believe that this value is incorrect. So you select a random sample of 900 children (age 2) and find that the mean cost is $8275 with SD of $1540. At = 0.01 is there enough evidence to conclude that the mean cost is different from $ 8390 ?