Answer:
Step-by-step explanation:
The formula for determining the confidence interval for the difference of two population means is expressed as
Confidence interval = (x1 - x2) ± z√(s²/n1 + s2²/n2)
Where
x1 = mean sale amount for mail order sales = 82.70
x2 = mean sale amount for internet sales = 66.9
s1 = sample standard deviation for mail order sales = 16.25
s2 = sample standard deviation for internet sales = 20.25
n1 = number of mail order sales = 17
n2 = number of internet sales = 10
For a 99% confidence interval, we would determine the z score from the t distribution table because the number of samples are small
Degree of freedom =
(n1 - 1) + (n2 - 1) = (17 - 1) + (10 - 1) = 25
z = 2.787
Margin of error =
z√(s²/n1 + s2²/n2) = 2.787√(16.25²/17 + 20.25²/10) = 20.956190
Answer:
yes the answer in 12 fpavers
Step-by-step explanation:
wa
The correct choice is B
x is greater than equals to -4.25
Answer:
B) (3,1)
Step-by-step explanation:
y = -2x + 7
y = 3x - 8
3x - 8 = -2x + 7
combine like terms:
5x = 15
divide both sides of the equation by 5:
x = 3
y = 3(3) - 8 = 1
Answer:
A. 
B. Perimeter = 190.6 yd
Step-by-step explanation:
A. Distance between P(10, 50) and R(80, 10):
(nearest tenth)
B. Distance around the park = Perimeter = PR + PQ + QR
PR = 80.6 yd
PQ = |50 - 10| = 40 yd
QR = |80 - 10| = 70 yd
Perimeter = 80.6 + 40 + 70
Perimeter = 190.6 yd
