Consider the investor in the text, seeking out companies with weekly turnover of at least £5000. He applies a one-tail hypothesis test to each firm, using the 5% significance level. State whether each of the following statements is true or false (or not known) and explain why.

(a) 5% of his investments are in companies with less than £5000 turnover.

(b) 5% of the companies he fails to invest in have turnover greater than £5000 per week.

(c) He invests in 95% of all companies with turnover of £5000 or over.