2019 Probability Distributions Level 3 External Worked Solutions

Worked solutions to the 2019 NCEA external for Level 3 Probability Distributions Correction at 3:10 - I entered the working out wrong in the calculator (switched 152.3 into 153.2). 152.3 - 3 x 7 = 131.3 and 152.3 + 3 x 7 = 173.3.