A recent survey of gasoline prices indicated that the nation

A recent survey of gasoline prices indicated that the national average was $4.098 per gallon. The Dallas Automobile Club claimed that gasoline in Texas was significantly lower than the national average. A survey covering 10 different suburbs in Dallas found the average price of gasoline to be $3.924 per gallon with a population standard deviation of $0.053. What critical value should be used to test the claim using = 0.01?   Answer should be rounded to two decimal places

Solution

critical value for alpha = 0.01

alpha / 2 = 0.005

critical value will be +/- 2.57