Answer: 9+d=x or x=9+d
d-the new dvds
x-the unknown total
9-the dvds Zeke owned before
55+ 50 would be 105 don’t forget the dollar sign when answering
Let X be the national sat score. X follows normal distribution with mean μ =1028, standard deviation σ = 92
The 90th percentile score is nothing but the x value for which area below x is 90%.
To find 90th percentile we will find find z score such that probability below z is 0.9
P(Z <z) = 0.9
Using excel function to find z score corresponding to probability 0.9 is
z = NORM.S.INV(0.9) = 1.28
z =1.28
Now convert z score into x value using the formula
x = z *σ + μ
x = 1.28 * 92 + 1028
x = 1145.76
The 90th percentile score value is 1145.76
The probability that randomly selected score exceeds 1200 is
P(X > 1200)
Z score corresponding to x=1200 is
z = 
z = 
z = 1.8695 ~ 1.87
P(Z > 1.87 ) = 1 - P(Z < 1.87)
Using z-score table to find probability z < 1.87
P(Z < 1.87) = 0.9693
P(Z > 1.87) = 1 - 0.9693
P(Z > 1.87) = 0.0307
The probability that a randomly selected score exceeds 1200 is 0.0307
Answer:
The prices at which manager predict that at least 55 hats will be sold would be would be of $38
Step-by-step explanation:
According to the given data we the following:
Number of hats sold at $18=115
The manager predicts at 3 less will sold for every rise in 1 $ for at least 55 hats.
Therefore, reduction in number=115 hats-55 hats=60
So, increase in price=reduction in number/number of hats manager predicts that will be sold for every $1 increase in price
increase in price=60/3=$20
Therefore, prices at which manager predict that at least 55 hats will be sold would be=$18+$20=$38
The prices at which manager predict that at least 55 hats will be sold would be would be of $38