Answer:
confidence interval = ( -0.38 , 0.08 )
Step-by-step explanation:
Given data :
n1 = 55 , n2 = 60 ,
Let P1 ( proportion of SUV sales at store A ) = 30 / 55 = 0.55
P2 ( sample proportion of SUV sales at store B ) = 42/60 = 0.70
The Z-value at 99% confidence Interval = 2.58
<u>Determine the 99% confidence interval for difference in proportion</u>
applying the formula below
( P1 - P2 ) ± Z (
Input values above into equation
confidence interval = ( -0.38 , 0.08 )