The average is defined as the sum of the items divided by the number of items. In this case the sum is 771.888. If we divide that by the number of items (4) we get 192.972. However, our answer typically cannot have more significant digits than the element having the least number of significant digits. Since one of the numbers has only one digit to the right of the decimal point, we would usually want to round our answer to one place as well. So 192.972 will round to 193.0.
