statistics
posted by Ronaldo .
à manufacturer of computers designed to aid social scientists in analyzing research data clams that his computers are opérational for at least 80 percent of the time. during the course of the year one computer was operational for 270 days. test, 1 percent confidence level, whether the manufacturer's claim was justified. use the rive step model clearly showing all steps.

You can try a proportional onesample ztest for this problem. Check a table for the critical value to compare to the test statistic. If the test statistic exceeds the critical value, then reject the null and accept the alternative hypothesis.