Answer:
Step-by-step explanation:
Part 1
P(z < -1.45)
Using the z score table
P =
Part 2
We solve using z score formula
z = (x-μ)/σ, where x is the raw score, μ is the population mean, and σ is the population standard deviation.
a) P(X >52)
x = 52
Mean = 60
Standard deviation = 8
z = 52 - 60/8
z = -1
P-value from Z-Table:
P(x<52) = 0.15866
P(x>52) = 1 - P(x<52) = 0.84134
b) P(48 < x < 64)
Vertex form is basically commplete the square
y=a(x-h)^2+k
y=x^2+14x+4
take 1/2 of 14 and square it, (7^2=49)
add that and its negative to right side
y=x^2+14x+49-49+4
factor perfect squaer
y=(x+7)^2-49+4
y=(x+7)^2-45
answer is A
