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:
D
Triangle Midsegment
5
10
Step-by-step explanation:
Got it right on the assignment on EDG2020 :)
Answer:
(-10,8)
Step-by-step explanation:
So our original point is (-6,9).
A translation of 4 units to the left means that the x-value would go left by 4. In other words, we subtract 4 to -6. We subtract because going to the left means that it's going to the negative direction.
A translation of down 1 unit means that the y-value would go down by 1. In other words, we subtract 1. Again, we subtract because going downwards means that it's going to the negative direction.
Therefore, the new point would be:

Answer:
- apple: £0.20
- banana: £0.60
Step-by-step explanation:
Let "a" and "b" represent the costs of one apple and one banana, respectively. Then the purchases can be written ...
4a +b = 1.40
7a +b = 2.00
Subtracting the first equation from the second gives ...
(7a +b) -(4a +b) = (2.00) -(1.40)
3a = 0.60 . . . . simplify
a = 0.20 . . . . . .divide by 3
Using this in the first equation, we have ...
4(0.20) +b = 1.40
b = 0.60 . . . . . subtract 0.80
The cost of an apple is £0.20; the cost of a banana is £0.60.