Mathematics 9709 · AS & A Level · The normal distribution
The normal distribution — practice question
The 124 Senior members of the Giraffes basketball club have heights that are normally distributed with mean 187.4 cm and standard deviation 6.4 cm.
(a)[4]
How many club members would be expected to have heights within 5 cm of the mean?
(b)[3]
The heights of the Junior members of the Giraffes club are normally distributed with mean 172.7 cm and standard deviation $\sigma$ cm. It is given that 23% of these members have height less than 170.3 cm. Determine the value of $\sigma$.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “$P\left(\frac{182.4-187.4}{6.4}<Z<\frac{192.4-187.4}{6.4}\right)$” …