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.
Plan an effective strategy for working through the course
Answer:
Q=4
15q-16=8q+12
7q-16=12
7q=28
Q=4
So, the right option is 1. so if my ans was helpful u can follow me.
6.5c + 9.7a = 1721.4
a = 4c
6.5c + 9.7(4c) = 1721.4
6.5c + 38.8c = 1721.4
45.3c = 1721.4
c = 1721.4 / 45.3
c = 38...so there were 38 childrens' tickets <==
and 152 adult tickets