Let me show you an example. A school proofread a ninth grade girl to take the 100 meter test, and the result of reaching the standard was 18 seconds. The results of eight girls in the first group were (where the positive sign means more than 18 seconds): - 1,+0.8, 0, - 1.2, - 0.1, 0,+0.5, - 0.6 to calculate the rate of reaching the standard. A negative sum of zero indicates that the score is less than or equal to 13 seconds, that is, there are 6 people who reach the standard, so the rate of reaching the standard=6 divided by 8 times 100%=75%
