The class interval that contains the median is 40 < h <= 50.
To find the class interval that contains the median, we first need to find the cumulative frequency.
Class Frequency Cumulative frequency
10 < h <= 20 7 7
20 < h <= 30 13 20
30 < h <= 40 14 34
40 < h <= 50 12 46
50 < h <= 60 16 62
60 < h <= 70 18 80
The median is the middle value in the data set when it is arranged in order.
Since we have 80 values, the median is the 40th value.
The cumulative frequency shows that the 40th value is in the class interval 40 < h <= 50.
Therefore, the class interval that contains the median is 40 < h <= 50.