Leaving Certificate Maths 2018 pp2 Q8

In this video I work through a Leaving Certificate past paper question on Statistics and Financial Maths. Z-Scores are used to work out probabilities of sample means. A 95% confidence interval for population proportions is worked out before some calculus is used to work out a maximum value and a geometric series is used in financial maths.
Note: z-score for 1.58 should read 0.9429