Exercise M9.30According to an article in The New York Times (5/12/2004), 19.3% of New York City adults smoked in 2003. Suppose that a survey is conducted to determine this year’s rate. Twelve out of 70 randomly chosen N.Y. City residents reply that they smoke. Conduct a hypothesis test to determine is the rate is still 19.3%.
The average age of De Anza College students in Winter 2006 term was 26.6 years old. An instructor thinks the average age for online students is older than 26.6. She randomly surveys 56 online students and finds that the sample average is 29.4 with a standard deviation of 2.1. Conduct a hypothesis test. (Source: http://research.fhda.edu/factbook/DA...t_da_2006w.pdf 4 )
In 2004, registered nurses earned an average annual salary of $52,330. A survey was conducted of 41 California nursed to determine if the annual salary is higher than $52,330 for California nurses. The sample average was $61,121 with a sample standard deviation of $7,489. Conduct a hypothesis test. (Source: Registered Nurses : Occupational Outlook Handbook : U.S. Bureau of Labor Statistics )
La Leche League International reports that the average age of weaning a child from breastfeeding is age 4 to 5 worldwide. In America, most nursing mothers wean their children much earlier.
Suppose a random survey is conducted of 21 U.S. mothers who recently weaned their children. The average weaning age was 9 months (3/4 year) with a standard deviation of 4 months. Conduct a hypothesis test to determine is the average weaning age in the U.S. is less than 4 years old. (Source: http://www.lalecheleague.org/Law/BAFeb01.html6 )