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 u = 25.50 mpg and a standard deviation of o = 2.25 mpg.
(a) What is the standard error of
X
the mean from a random sample of 25 fill-ups by one driver? (Round your answer to 4 decimal places.)
Standard error of
х
.45
(b) Within what interval would you expect the sample mean to fall, with 98 percent probability? (Round your answers to 4 decimal
places.)
The interval is from