Healthcare expenditure of households in Sarail have a mean of 1200 taka per month with a standard deviation of 360 taka per month. Let x be the mean monthly healthcare expenditure for a random sample of 64 households from this city. (a) Find the probability that the mean monthly healthcare expenditure of households is not 2 less than 1280 taka per month. (b) What would be the error margin for any 99% confidence interval of mean monthly 2 healthcare expenditure? (c) What would be the minimum population in Sarail to avoid finite population correction? 1