WAEC - Geography (1997 - No. 12)
The mean annual range of temperature of a place is obtained by
adding the monthly mean temperatures for one year and dividing them by 12
adding the lowest temperature for one year to the highest for the year
subtracting the lowest mean daily temperature from the highest mean daily temperature for the year
adding the mean daily temperatures for one year and dividing by 365
subtracting the lowest mean monthly temperature from the highest mean monthly temperature for the year