In: Math
Fill in the blanks for "x" and "y". ) A bulk supply of CAT6 cables were purchased to implement a wired office network. The network designer randomly tests 12 of the cables and finds the attenuation is on average 22.7dB with a sample standard deviation of 1.9 dB. She wishes to estimate the 95% confidence interval for the mean attenuation of all of the cables. Find the 95% confidence interval (α=0.05) for the mean attenuation rounded to the
We have given that,      
       
          
   
Sample mean =22.7      
Sample standard deviation =1.9  
Sample size =12      
Level of significance=1-0.95=0.05  
   
Degree of freedom =11      
          
   
t critical value is (by using t table)=2.201  
   
          
   
Confidence interval formula is   

=(21.49,23.91)      
          
   
          
   
          
   
Lower confidence limit=21.49  
          
   
Upper confidence limit=23.91