(a)A family restaurant wants to estimate the mean amount that customers spend on their dinner between Monday and Friday. Find the 95% confidence interval estimate of the mean given the following random sample of $131, $118, $95, $110, $105, $65, $84, $123, $80....................................................... 1.5 mark

(b)A survey conducted by a pharmaceutical company found that the probability of success in the clinical trial is 0.75. Suppose five hundred clinical trials are performed in the study, what is the probability of succeeding in the clinical trial between 275 and 420 times? Use normal approximation of the binomial distribution.1 mark

(c)An airline company found that 395 out of 800 travellers cancelled their airline bookings after they had selected their flight details. At 0.01 level of significance, is there evidence that the population proportion of travellers who select their flights and cancel their bookings is less than 0.45?............................................. 1.5 mark