Question

A random sample of 100 Texas law firms was selected to determine the degree of computer usage in the firms. The survey showed that 72 of the firms used microcomputers (PC's). From the information above, estimate the proportion of all Texas law firms that use PCs with a 98% confidence interval for p. Round your answer to four decimal places.

Answer 1

We have given,              
              
x=72          
n=100          
Estimate for sample proportion=
Level of significance is =1-0.98=0.02      
Z critical value(using Z table)=2.33  
      
Confidence interval formula is              


=(0.6155,0.8245)

              
Lower limit for confidence interval=0.6155
              
Upper limit for confidence interval=0.8245