1) Test a Has Mean Score of 45 with a Standard Deviation of 3.5 and Test B Has a Mean Score

AP Review #2

1) Test A has mean score of 45 with a standard deviation of 3.5 and test B has a mean score of 20 and a standard deviation of 1.75. Ralph scored a 50 on test A and Louise scored a 22 on test B. Who had the better score?

2) Tree ring dates are used extensively in archeological studies at Burnt Mesa Pueblo. At one sight on the mesa, tree ring dates (from many samples) gave a mean date year 1272 with standard deviation 35 years. At a second site, the tree ring dates gave a mean year 1122 with a standard deviation of 40 years. Assume that both sites had dates that were approximately normally distributed. In the first area an object was found and dated year 1250. In the second area another object was found and dated year 1234. Which of these two items is the more unusual as an archeological find in its location? Explain.

3) Girls at CHHS have an average height of 65.5 inches with standard deviation of 2.3 inches. Boys have an average height of 71 inches with a standard deviation of 3.5 inches. If girls and boys were picked at random and the difference in height calculated, what would the average height difference be? What would the standard deviation of the differences in height be?

4) According to government data, 20% of employed women have never been married. a) If 10 employed women are selected at random, what is the probability that exactly 2 have never been married? b) That at most 2 have never been married? c) That at least 8 have been marred?

5) For the following question, state the hypotheses, the type I & type II errors, and the consequences for each. A manufacturer of handheld calculators receive very large shipments of printed circuits from a supplier. It is too costly and time consuming to inspect all incoming circuits, so when each shipment arrives, a sample is selected for inspection. The shipment is rejected and returned to the supplier if the proportion of defective circuits is more than 5%.

6) Polly and Pete go through one page from a telephone book and write down the last digit of 50 telephone numbers. Could the last digit from the phone numbers on this page be used as random digits? Digit: 0 1 2 3 4 5 6 7 8 9 7 6 3 2 5 7 2 10 8 0

7) The following data are based on the results of a survey to examine media preferences. Does the evidence support the claim that the type of media preferred and age group are independent?

TV Fans Radio Listeners Newspaper Totals Readers 18 to 34 29 41 31 35 to 49 22 27 29 50 or older 50 32 40 Totals