Question

A random sample of 5 fields of rye has a mean yield of 21.3 bushels per acre and standard deviation of 2.53 bushels per acre. Determine the 99% confidence interval for the true mean yield. Assume the population is approximately normal. Step 1 of 2 : Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

Answer 1

We have given that,          
          
Sample mean =21.3 bushels per acre  
Sample standard deviation =2.53 bushels per acre
Sample size =5  
Level of significance=1-0.99=0.01  
Degree of freedom =4  
          
t critical value is (by using t table)=   4.604  
          
Confidence interval formula is


=(16.091,26.509)          
          
          
          
Lower confidence limit=   16.091 bushels per acre
          
Upper confidence limit=   26.509 bushels per acre