First, let us count how many X and Y values there are in the image. Counting each individual number, we have 25 rows and 2 columns(X and Y), so there are 25×2=50 pairs of X and Y values. So there are 50 X values and 50 Y values in total. Next, we add all the X values together.
70.3+81.3+85.4+72.3+82.4+76.7+77.8+76.6+78.1+76.7+80.0+78.3+75.2+75.3+74.0+77.4+78.9+77.2+76.5+78.3+69.5+81.7+82.6+82.3+75.0+72.7+83.8+84.4+78.0+76.2+74.2+77.7+77.1+81.3+76.5+79.9+78.2+81.2+80.6+80.4+66.1+90.9+91.5+87.7+75.3+87.0+82.6+79.7+87.6+82.4+77.0+79.8+79.3+79.2+79.7+80.8+79.2+81.0+78.9+76.5+82.3+76.8+73.6+84.1+79.0+80.7+76.3+83.0+75.9+76.0+81.1+80.3+72.6+75.4+73.5+80.7+78.9+78.3+76.1+80.1+82.3+70.3+76.1+67.7+72.1+77.9+78.8+85.3+84.2+73.2+80.3+78.4+77.2+77.8+79.1+76.2+77.1+77.2+76.6+78.5=3870.5 Then, we add all the Y values together.
91.4+90.7+86.2+56.3+92.3+81.3+69.4+75.5+81.3+87.3+72.2+83.2+74.2+84.4+79.6+73.3+73.7+81.9+82.3+80.1+64.7+70.7+89.0+78.3+80.8+79.9+75.6+82.2+67.2+80.1+75.3+79.9+85.0+77.6+77.8+73.6+80.4+80.7+81.7+74.0+82.4+82.0+72.0+66.8+72.5+86.7+69.8+78.4+77.4+80.0+74.5+77.3+68.1+85.2+81.5+77.7+73.0+81.4+79.5+72.5+98.6+69.1+75.3+81.9+92.8+66.1+68.7+69.7+75.9+68.1+81.9+82.0+73.0+79.7+75.9+73.0+76.7+73.7+75.5+80.7+94.6+59.5+62.0+64.2+84.0+83.5+81.8+86.9+76.2+87.8+69.3+70.1+77.7+83.3+73.1+80.9+79.8+80.5+77.4+78.2=3865.9 Finally, we find the averages by dividing by the number of values.
Average of X values = 3870.5/50=77.41 Average of Y values = 3865.9/50=77.318