To find the approximate difference between the means of the two data sets, you simply subtract the mean rainfall of the Lowlands from the mean rainfall of the highlands.
Given:
- Mean rainfall in the Highlands = 15.27 mm
- Mean rainfall in the Lowlands = 12.05 mm
Calculating the difference:
\[ \text{Difference} = 15.27 , \text{mm} - 12.05 , \text{mm} = 3.22 , \text{mm} \]
Now, rounding this difference to the nearest whole number:
\[ \text{Difference} \approx 3 , \text{mm} \]
Therefore, the approximate difference between the means of the two data sets to the nearest whole number is 3 mm.