Question

When 20 campers are randomly selected and surveyed, it was found that the average number that prefer to camp at the beach was 77. Assume the population standard deviation is 13.2. Construct a 90% confidence interval for the true population mean of the number of campers who prefer to camp at the beach.

Give your answers to 2 decimal places.
Error =
< μμ <

Answer 1

We have given that,          
          
Sample mean =77  
Population standard deviation=   13.2
Sample size=20  
Level of significance =1-0.90=0.1  
Z critical value (by using Z table)=1.645  

Margin of error

E=4.86