Answer:
D) 1980 to 2000
Step-by-step explanation:
Finding the average rate of change in each interval to determine the greatest one.
Production per interval
1950-1960 = = 10 million
1960-1970 = = 20 million
1970-1980 = = 30 million
1980-2000 = million
Rate of change (1950-1960)=
Rate of change (1960-1970) =
Rate of change (1970-1980)=
Rate of change (1980-2000)=
∴ rate of change between 1980 to 2000 is 126.78%
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