ll 2} 3i 4i The following table gives the percentage distribution of the 1992 U.S. labor force by educational attainment: Educational Attainment Percentage of Workers Less than a high school diploma 12.4 High school graduates 35.? Some college but no degree 13.0 Associate degree 14 Bachelor's degree 1?.2 Master's degree 6.5 Professional or doctoral degree 2.8 A recent sample of 1000 workers showed that 116 have less than a high school diploma, 363 are high school graduates with no college, 164 have some college but no degree, 71 possess an associate degree, 187 hold bachelor's degree, and 61 have a master's degre e, and 38 possess a professional or doctoral degree. Test at 1% signicance level if the percentage distribution of the U.S. labor force by education attainment has changed since 1992. A large departmental store records the number of returns per day in women's dresses for reasons such as wrong size; husband didn't like it, colour, etc. The manager of the women's dresses department recalls from her statistics class in college that the Poisson distribution might describe such events. A random sample of 150 days is taken. The number of returns per day in the sample as well as the observed frequencies are shown in the table below: Number of Returns Per Test the hypothesis that returns per day are Poisson distributed at 5% level of significance . DOM Corporation owns department stores in almost all states. Forty eight percent of all persons who possess credit cards for these department stores usually make payment on their credit card bills within 15 days of the issue of the statement, 44% pay within 16 to 30 days, and 8% take more than 30 days to pay. The management wants to know if the credit card holders in a specific state are different from the credit card holders in other states. The research department at the company took a random sample of 800 credit card holders from this state and found that 397 of them made the payment on their credit card bills within 15 days of the issue of the statement, 342 paid within 16 to 30 days, and 61 took more than 30 days to pay. Test at 2.5% significance level if the credit card holders in this state are different from all credit card holders with respect to making payments on their credit card bills. Home Mail Corporation sells products by mail. The company's management wants to find out if the number of orders received at the company's office on each of the five days of the week is the same. The company took a sample of 400 orders received during a four week period. The following table lists the frequency distribution for these orders by the day of the week: Day of the Week Mon Tue Wed Thu Fri Number of orders received 92 3'1 65 33 39