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
Its C)126in I think because top base is 16, bottom base is 12 and the height is 9.
Sure, each of the following lines.
8x-6+3x-1
11x-6-1
and, 11x-7
Answer:
25.5 and 37.5
Step-by-step explanation:
x+y=63
x-y = 12 then x = 12 + y sub this into the first equation
(12+y) + y = 63
12 + 2y = 63
2y = 51
y = 25.5 then x = 37.5
Answer:
c.63
will be your answer
Step-by-step explanation: