The length of needles produced by a machine has standard deviation of 0.04 inches. Assuming that the distribution is normal, how large a sample is needed to determine with a precision of ±0.005 inches the mean length of the produced needles to 98% confidence?

The sample size is  

Step-by-step explanation:

From the question we are told that

      The standard deviation is  

       The  precision is

        The confidence level is 98%

Generally the sample size is mathematically represented as  

Where    is the level of significance which is mathematically evaluated as

        %

and   is the critical value of which is obtained from the normal distribution table as  2.326

  substituting values

on the middle line

step-by-step explanation:

1/5=50

the answer is about 24 dollars