| A | B | C | D | And | |
Sample size | 100 | 99 | 100 | 86 | 100 | |
Get to the bottom of the grades | 41.23 ± 8.17 | 41.14 ± 7.47 | 42.76 ± 7.67 | 36.26 ± 6.27 | 43.18 ± 8.28 | |
Measured results | 41.31 ± 10.04 | 42.41 ± 8.62 | 41.46 ± 8.04 | 39.08 ± 9.13 | 45.74 ± 8.16 | |
T | 0.112 | 2.252 | −1.912 | 3.788 | −4.202 | |
P | 0.911 | 0.027 | 0.059 | <0.05 | <0.05 |