A major department store chain is having an end of the seaso

A major department store chain is having an end of the season sale on refrigerators. The number of refrigerators sold during the sale at a sample of 10 stores was:

80, 110, 0, 40, 70, 80, 100, 50, 80, 30

A) Is there any evidence that the average of more than 50 refrigerators per store were sold during this sale?

B) what is the sample mean? what is the sample standard deviation?

C) what is the sample error and confidence interval?

D) What is the T statistics?

Solution

Set Up Hypothesis
Null, H0: U=50
Alternate, H1: U>50
Test Statistic
Population Mean(U)=50
Sample X(Mean)=64
Standard Deviation(S.D)=33.731
Number (n)=10
we use Test Statistic (t) = x-U/(s.d/Sqrt(n))
to =64-50/(33.731/Sqrt(10))
to =1.312
| to | =1.312
Critical Value
The Value of |t | with n-1 = 9 d.f is 1.833
We got |to| =1.312 & | t | =1.833
Make Decision
Hence Value of |to | < | t | and Here we Do not Reject Ho
P-Value :Right Tail - Ha : ( P > 1.3125 ) = 0.11092
Hence Value of P0.05 < 0.11092,Here We Do not Reject Ho

ANSWERS)
A.
No, we don\'t have evidence that the average of more than 50 refrigerators per store were sold

B.
Sample X(Mean)=64
Standard Deviation(S.D)=33.731

C.
Standard Error= sd/ Sqrt(n)
Standard Error = ( 33.731/ Sqrt ( 10) )
= 10.667

D.
to =1.312