Question

1) For 31 randomly selected Rolling Stones concerts, the mean gross earnings is 2.61 million dollars. Assuming a population standard deviation gross earnings of 0.5 million dollars, obtain a 99% confidence interval (assume C-Level=0.99) for the mean gross earnings of all Rolling Stones concerts (in millions). Confidence interval: ___,___

2) correct interpretation for part 1 answers?

a. 99% chance that the mean gross earnings of all rolling stones concerts lies in the interval

b. 99% confident that the mean gross earning for this sample of 31 rolling stones concerts lies in the interval

c. 99% confident that the mean gross earning of all rolling stones concerts lies in the interval

d. none of the above

Answer 1

We have given that,                              
                              
Sample mean =2.61 million dollars.                       
Population standard deviation=0.5 million dollars.                   
Sample size=31                      
Level of significance =1-0.99=0.01                      
Z critical value (by using Z table)=2.58                      
                              
Confidence interval formula is


=(2.38,2.84)                              
                              
Lower confidence limit =2.38 million dollars.                   
Upper confidence limit =2.84 million dollars.       

c. 99% confident that the mean gross earning of all rolling stones concerts lies in the interval