(a(i))[3]
The magazine has, on average, 1 incorrect character in every 540 characters. Use a suitable approximating distribution to determine the probability that a magazine with 2430 characters contains at least 4 incorrect characters.
(a(ii))[1]
Justify the choice of approximating distribution.
(b(i))[1]
The mean monthly number of copies, $X$, of the magazine sold is 123.4. State one condition needed for $X$ to follow a Poisson distribution.
(b(ii))[5]
You are now told that $X$ has a Poisson distribution. Use an appropriate approximating distribution to determine the probability that, in a randomly chosen month, more than 130 copies of the magazine are sold.