Dress Shirts In a previous study conducted several years ago, a man owned on average 14 dress shirts. The standard deviation of the population is 2. A researcher wishes to see if that average has changed. He selected a random sample of 44   men and found that the average number of dress shirts that they owned was   13.9. At α=0.05, is there enough evidence to support the claim that the average has changed? Assume that the variable is normally distributed. Use the   P-value method with a graphing calculator.  Find the P-value. Round the answer to at least four decimal places.  P-value=

Dress Shirts In a previous study conducted several years ago, a man owned on average 14 dress shirts. The standard deviation of the population is 2. A researcher wishes to see if that average has changed. He selected a random sample of 44 

 men and found that the average number of dress shirts that they owned was  

13.9. At α=0.05, is there enough evidence to support the claim that the average has changed? Assume that the variable is normally distributed. Use the  

P-value method with a graphing calculator. 

Find the P-value. Round the answer to at least four decimal places. 

P-value= 

Student Expenditures The average expenditure per student (based on average daily attendance) for a certain school year was $10,337 with a population standard deviation of $1560. A survey for the next school year of 174 randomly selected students resulted in a sample mean of $10,547. Do these results indicate that the average expenditure has changed? Use α=0.05. Use a graphing calculator. 

Find the P-value. Round the answer to at least four decimal places. 

P-value= 

Weight Loss of Newborns An obstetrician read that a newborn baby loses on average 7 ounces in the first two days of his or her life. He feels that in the hospital where he works, the average weight loss of a newborn baby is less than 7 ounces. A random sample of 33 newborn babies has a mean weight loss of 6.6 ounces. The population standard deviation is 1.8 ounces. Is there enough evidence at  

α=0.05 to support his claim? Assume that the variable is normally distributed. Use the  

P-value method with a graphing calculator. 
P-value= 

Daily Driving The average number of miles a person drives per day is  

1. 24. A researcher wishes to see if people over age 60 drive less than 24

 miles per day. She selects a random sample of 32 drivers over the age of  

60 and finds that the mean number of miles driven is 22.9. The population standard deviation is 3.1 miles. At α=0.05, is there sufficient evidence that those drivers over  

60 years old drive less than 24 miles per day on average? Assume that the variable is normally distributed. Use the P-value method with a graphing calculator.