Answer:
Step-by-step explanation:
We know that when X is normal
X-mu/sigma is std normal
Here the scores X is normal with mean =140 and sd =40
a) X=172
gives Z = 32/40 = 0.80
P(Z<0.8) = 0.5+0.2881
=0.7881
Hence 79th percentile
b) X =200 then x-mu = 60
So z=60/40 = 1.5
c) 100<x<160 means
1.5<z<0.5
d) X>190 means Z>1.25 hence proportion = P(Z>1.25) =0.5-0.3944
=0.1056
e) For 67th percentile z value = 0.0675
Hence x score = 140+0.0675(40) = 142.7
Answer:
2
Step-by-step explanation:
The slope of a line given two points is found by
m = (y2-y1)/(x2-x1)
= (3-5)/(-2- -1)
=(3-5)/(-2+1)
= -2/-1
=2
Step-by-step explanation:
cos(x) = adjacent / hypotenuse
Let c be children and a adults.
3.5c + 7a = 1771 (the total revenue is equal to the amounts made off of people)
c + a = 331 (total number of people)
The second formula becomes a = 331 - c. This can be substituted into the first formula.
3.5c + 7(331 - c) = 1771 = 7*331 - 3.5c = 1771. 7*331 = 2317, so 3.5c = 2317 - 1771 = 546.
546/3.5 = 156 = c (number of children).
c + a = 156 + a = 331 => a = 331 - 156 = 175 (number of adults).
There are 156 children and 175 adults
