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:
(-2+-5) equals -7.
Because the signs are the same, we dont change it.
(3+5) equals 8. Same like the other equation, the signs are the same so we do not change it.
Now we do (-7+8) The answer will be 1. Lets use a little graph since its hard to explain.
-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8
Mark -7 anyway you want. (Circle it, draw a line under it, what ever you want.)
Now Move the line 8 times.
When you do that your line will stop at 1.
And thats how you do it.
Step-by-step explanation:
Hey again!
The answers for your question is A; Positive, and C; no association
Answer:
the two numbers are 12 and -29
Step-by-step explanation:
let the two numbers be x and y
let the sum of the two numbers b
x+y = -17 ..................................................... equation 1
let the difference between the two numbers be
x-y = 41 ........................................................................ equation 2
from equation 1
x+y = -17 ..................................................... equation 1
x = -17 - y ............................................................... equation 3
substitute for x in equation 2
x-y = 41 ........................................................................ equation 2
-17-y -y = 41
-17 -2y = 41
-2y = 41 + 17
-2y = 58
divide both sides by -2
-2y/-2 = 58/-2
y = -29
put the value of y = -29 in equation 3
x = -17 - y ............................................................... equation 3
x = -17-(-29)
x =-17 + 29
x = 12
therefore the two numbers are 12 and -29
Answer:
360 centimeters squared
Step-by-step explanation:
