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 )
Answer:
The solution is in the image
Answer:
The price that is two standard deviations above the mean price is 4.90.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean and standard deviation
, the z-score of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Mean of 3.22 and a standard deviation of 0.84.
This means that
Find the price that is two standard deviations above the mean price.
This is X when Z = 2. So
The price that is two standard deviations above the mean price is 4.90.