There are several thousand machinery rebuilding and repairing companies in the USA. A tool manufacturer wishes to survey a simple random sample of these firms to find out what proportion of them is...

There are several thousand machinery rebuilding and repairing companies in the USA. A tool manufacturer wishes to survey a simple random sample of these firms to find out what proportion of them is interested in a new tool design. If the tool manufacturer would like to be 95.0 % confident that the sample proportion is within .04 of the actual population proportion, how many machinery repairing and rebuilding companies would he include in the sample?