(8/9)^2 is just 8/9 squared, or 8/9 * 8/9. This is 64/81, and cannot be reduced. This is therefore our answer.
Let get all the information.
Mean:394
Deviation:35
Looking for At Least 380 feet
To find the z score you take the wanted probality subtract the mean and divide by the deviation.
z=(380-394)/35.
z=-0.4
So far so good.
But when he looked at the table he looked at probability that the home runs are less then 380 feet.
From this table
http://www.stat.ufl.edu/~athienit/Tables/Ztable.pdf
To find the answer you have to take 1-(the probability that the home runs are less than 380 feet)or 1-0.3446=0.6554
He made an error in his calculation.
Answer:
The airplane can fly up to 240 miles in a hour
Step-by-step explanation:
Cross multiply
(12)(60)=3x
720=3x
Divide 3 on both sides
x=240
The fraction equal to .66 is <span>33⁄50</span>