A national publishing house claims that 37% of all weekly magazine reader sin South Africa read their publication. Test this claim at the 1% significance level, if a survey found that 140 out of a random sample of 400 magazine-readers said that they read the relevant publication. The CEO of a large financial institution claims that, on average, their clients invest more than R45 000 per year in a particular portfolio. Test this claim at the 5% significance level if it was found that a sample of 21 clients invested an average of R44 500 in the portfolio over the last year, with a standard deviation of R5 500.