5 The lengths of the leaves of a particular type of tree are modelled by a normal distribution. A scientist measures the lengths of a random sample of 500 leaves from this type of tree and finds that 42 are less than 4 cm long and 100 are more than 10 cm long.
- Find estimates for the mean and standard deviation of the lengths of leaves from this type of tree.
The lengths, in cm , of the leaves of a different type of tree have the distribution \(\mathrm { N } \left( \mu , \sigma ^ { 2 } \right)\). The scientist takes a random sample of 800 leaves from this type of tree. - Find how many of these leaves the scientist would expect to have lengths, in cm , between \(\mu - 2 \sigma\) and \(\mu + 2 \sigma\).