Since she started out with 40,000 miles, you have to subtract that from 44,800 miles. you end up with 4,800 miles. you then divide 4,800 miles by 800 miles and you end up with 6 as your answer.
Let X be the score on an english test which is normally distributed with mean of 31.5 and standard deviation of 7.3
μ = 31.5 and σ =7.3
Here we have to find score that separates the top 59% from the bottom 41%
So basically we have to find here x value such that area above it is 59% and below it is 49%
This is same as finding z score such that probability below z score is 0.49 and above probability is 0.59
P(Z < z) = 0.49
Using excel function to find the z score for probability 0.49 we get
z = NORM.S.INV(0.49)
z = -0.025
It means for z score -0.025 area below it is 41% and above it is 59%
Now we will convert this z score into x value using given mean and standard deviation
x = (z* standard deviation) + mean
x = (-0.025 * 7.3) + 31.5
x = 31.6825 ~ 31.68
The score that separates the top 59% from the bottom 41% is 31.68
2/7 not sure but that's what i got
100,000,000+3,000,000+700,000+20,000+7,000+400+90+5 hope this helps
