91影视

The given data is shown below:

The data values are:

12, 17, 18, 21, 23, 23, 23, 24, 25, 25, 25, 26, 28, 29, 30, 31, 31, 32, 33, 33, 34, 35, 35, 36, 36, 36, 37, 38, 38, 38, 38, 38, 39, 39, 39, 39, 39, 39, 40, 40, 41, 41, 41, 43, 43, 43, 43, 44, 45, 45, 46, 46, 47, 53

As we know that median is the middle value of a data set. As the given set is even, the median will be the middle values (27th and 28th) of this sorted data:

$$\begin{gathered} M=\frac{37+38}{2} \\ =\frac{75}{2} \\ =37.5 \end{gathered}$$

Therefore, the median is 37.5 birth per 1000 individuals.

We can observe that most of the values in the dot-plot are to the right, with a tail of more rare (small) values to the left, the distribution is skewed to the left.

The mean is lower than the median in a left-skewed distribution because the mean is influenced more by the abnormally tiny data values in the data set.