9. Let X denote the number of heads that appear when five coins are tossed. X is assumed to follow a binomial distribution with b( i; 5, p), where i = 0, 1,...,5 and p = 0.5. The following data records the frequency distribution of the number of heads in 50 tosses of the five coins. Number Observed of heads frequency 17 15 10 Test the hypothesis that the data can be fitted by a binomial distribution with p = 0.5 using a = 0.05