Normal Distribution
The normal distribution can be described by two parameters: the mean and the standard deviation.
We are given the parameters of a normal distribution as follows:
Mean = 18
SD = 4
A value of 24 is 24 - 18 = 6 units away from the center of the distribution, or the mean value.
Calculating the ratio of 6 units by 4 units, we get 6 / 4 = 1.5
This means the given value is 1.5 standard deviations away from the mean