9709 P62 - Nov 2019 - Q6
3199
In another forest, the heights of another type of fir tree are modelled by a normal distribution. A scientist measures the heights of 500 randomly chosen trees of this type. He finds that 48 trees are less than 10 m high and 76 trees are more than 24 m high.
Find the mean and standard deviation of the heights of trees of this type.
