# Studies shown that gasoline use for compact cars sold in the U.S. is normally distributed, with a mean of 25.5 mpg and standard deviation of 4.5 mpg.

Studies shown that gasoline use for compact cars sold in the U.S. is normally distributed, with a mean of 25.5 mpg and standard deviation of 4.5 mpg. Find the range of mileage for the middle 60% of compact cars.

I believe that you subtract x from 25.5 then divide by 4.5. find x and then place it into 25.5+(x)(4.5). but I do not know what to do with the 60%

• If you look at a standard normal table, you will see that $60\%$ of the probability lies between $z=-0.84$ and $z=0.84$. So for the cars the range will be $25.5\pm (4.5)(0.84)$. – André Nicolas Nov 18 '14 at 15:17

Random Variable $MPG$: $M$iles $P$er $G$allon
Possible Values $mpg$: [$0$ mpg, $600$ mpg]
Determine $mpg_1$ and $mpg_2$: $P$($mpg_1$ $\le$ $MPG$ $\le$ $mpg_2$) $= 0.60$.