Question

A manufacturer of college textbooks is interested in estimating the strength of the bindings produced by a particular binding machine. Strength can be measured by recording the force required to pull the pages from the binding. If this force is measured in pounds, how many books should be tested to estimate with 98% confidence to within 0.05 lb, the average force required to break the binding? Assume that σ is known to be 0.7 lb. (Use the value of z rounded to two decimal places.)
A) _______

Answer 1

We have given here,              
              
Population standard deviation =   0.7
Margin of error =E=0.05
Level of significance =   1-0.98=0.02
Z critical value is (by using Z table) =2.33

Sample size formula is

  

=1060.73
              
Therefore, sample size approximately will be 1061