The study mentioned in the previous exercise estimated in 2010 that 3% had done better in interschool competitions because of reading such books; this was 4.5% at the latest survey.

(a) Specify assumptions, notation, and hypotheses for a two-sided test comparing the corresponding population proportions.

(b) The test statistic z = 5.53 and the P-value close to 0.0000. Interpret the P-value.

(c) Some might argue that the result in

(b) reflects statistical significance but not practical significance. Explain the basis of this argument, and explain why you learn more from the 95% confidence interval, which is (0.009, 0.02).