Let k be a binomial random variable based on a distribution with parameters n = 310 and p = 0.45. a) Write down (but do not evaluate) an expression for the exact probability that k lies between 155...

Let k be a binomial random variable based on a distribution with parameters n = 310 and p = 0.45. a) Write down (but do not evaluate) an expression for the exact probability that k lies between 155 and 245 inclusive. b) Write down *and* evaluate an expression based on the normal distribution that approximates this probability.