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).

The answer is 0.72 ± 0.088

This numbers indicate that the number that shown based on the samples almost reflect the truth in actual truth with potential 5% of significant mistakes.

For average researchers, the data will be considered as 'desirable' if it showed 95% - 99% confident interval.