The highway fuel economy of a 2016 Lexus RX 350 FWD 6-cylinder 3.5-L automatic 5-speed using premium fuel is a normally distributed random variable with a mean of = 23.50 mpg and a standard deviation of = 3.00 mpg.

a) What is the standard error of X-(the - goes over the x) , the mean of from a random sample of 25 fill-ups by one driver? (Round your answer to 4 decimal places)

Standard error of X- (the - goes over the x)is: _____

b) Within what interval would you expect the sample mean to fall, with 98 percent probability? (Round your answer to 4 decimal places)

The interval is from _____ to ____