An investigator is interested in the amount of credit card debt accrued by

# An investigator is interested in the amount of credit

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6. An investigator is interested in the amount of credit card debt accrued by adults in his town. He takesa simple random sample of 100 adults, and finds that for his sample, the average debt is \$12,500, withan SD of \$3,600.(a) (2 points) Using this information, can he construct an approximate 90% confidence interval for theaverage debt of adults in his sample? If yes, then calculate and interpret the confidence interval. Ifno, then why not? (b) (2 points) Using this information, can he construct an approximate 90% confidence interval for theaverage debt of adults in his town? If yes, then calculate and interpret the confidence interval. Ifno, then why not? (c) (1 point) Because the sample size is large, the Central Limit Theorem says that theisroughly normal (fill in the blank by circling one of the following):
Stat 20 Final Exam, Page 10 of 14 9 August 2012 7. According to the Census Department, 52.5% of all children born in the United States in 2008 were male,while 47.5% were female.An investigator believes that in her city, there are a higher percentage offemales born than in the country as a whole. She decides to perform a statistical test.(a) (2 points) State the investigator’s null and alternative hypotheses. What kind of test should sheperform?