Answer: 12
Step-by-step explanation:
This is a direct proportion and we use the formula:
y = kx
If y = −4 when x=2, we need to find the constant of proportionality. This will be:
y = kx
-4 = 2k
k = -4/2
k = -2
To find y when x=−6 guess this:
y = kx
y = -2 × -6
y = 12
Let P=Perm cost
Let H = Haircut cost
Let L = Lunch cost
Perm costs twice as much as haircut so.. P = 2H
L = 5
H + P + L = 68 the total cost is $68
H + 2H + 5 = 68 since P = 2H and L=5
3H + 5 = 68
3H =63
H = 63/3
H = 21
A Haircut is $21
Perm = 2H = 2(21) = $42
Mean = (89 + 90 + 87 + 95 + 86 + 81 + 102 + 105 + 83 + 88 + 91 + 79)/12 = 1,076/12 = 89.67
a.) 95% C.I. = 89.67 + or - 1.96(0.23) = 89.67 + or - 0.4508 = 89.22 to 90.12
b.) 99% C. I = 89.67 + or - 2.575(0.23) = 89.67 + or - 0.5923 = 89.08 to 90.26
She is incorrect because x^2 can still be factored.
