A current gasoline survey said that national average gasoline price was $1.298 a gallon. It was felt that gasoline in Texas was significantly lower than the national average. A survey of 7 different suburbs in Dallas, Texas, found the average price of gasoline to be $1.173 a gallon with a standard deviation of $0.0436. What is the test value?
a) -4.38
b) -5.41
c) -6.19
d) -6.43
e) -7.59
f) -10.7
g) none