1. The U.S. Department of agriculture reports that the mean cost of raising a child from birth to a age of 2 in a rural area is $9405. You believe this value is incorrect so you select a random sample of 900 children and find the mean cost is $9290 with a standard deviation of $1540. At alpha = 0.05 is there enough evidence to conclude the mean cost is different from $9405.

2. In Illinois, a random sample of 85 eight grade students has a mean score of 265 with a standard deviation of 55 on a national mathematics assessment test. The result prompts a state school administrator to declare that the mean score for the states eight grades on the examination is 260. At alpha = 0.04 is there enough evidence to support the administrators claim.

3. An automotive battery manufacturer guarantees that the mean reserve capacity of a certain batter is 15 hours. To test this claim you randomly select a sample of 50 batteries and find the mean reserve capacity to be 15.5 hours with a standard deviation of 0.32 hours. At alpha = 0.10 do you have enough evidence to support the manufacturers claim.

4. An Alabama politician claims that the mean annual salary for engineering managers in Alabama is $90,900. A sample of 34 engineering managers in Alabama is listed below. At alpha = 0.03 see if the data supports the politicians claim.

87,512 89,510 82,639 98,897 104,877 87,592

103,632 105,202 93,672 104,878 101.508 88,302

89,231 105,060 95,974 76,955 101,396 69,838 87,728 98,314

104,349 93,493 74,918 89,736 68,060 96,777 82,723 92,944 86,114

97,062 85,975 84,956 95,905 79,042