Mathematics (AS & A Level) · Feb / March 2018 · Paper 72 · Question 2

The number of phone calls arriving in a 10-minute period at a switchboard is modelled by the random variable X which has the distribution Po4.1 . Use an approximating distribution to find the probability that more than 90 calls arrive in a 4-hour period. [5]

Read automatically from the paper; the printed page above is exact.