Answer:
$1226.78<x<$1301.22
Step-by-step explanation:
The formula for calculating confidence interval is expressed as;
CI = xbar ± z×(s/√n)
Given
Mean (xbar) = $1264
z is the z score at 90% CI = 1.645
s is the standard deviation = $150
n is the sample size = 44
Substitute
CI = 1264±1.645(150/√44)
CI = 1264±1.645(150/6.63)
CI = 1264±1.645(22.624)
CI = 1264±37.22
CI = (1264-37.22, 1264+37.22)
CI = (1226.78, 1301.22)
Hence the confidence interval of the mean is $1226.78<x<$1301.22
Answer:
B 98
Step-by-step explanation:
4*7=28 times 3 = 84
3.5*4=14
84+14=98
Hope this helps! :)
The correct simplification of the expression is 9c^2 i think.
