区间

$n_i$

$F(·)$

${\widehat{p}}_i$

$n{\widehat{p}}_i$

$\frac{{\left(n_i-n{p}_i\right)}^2}{n{p}_i}$

( $-\infty$ ,38]

7

0.10

0.10

6.98

0.00

(38,40]

10

0.23

0.13

9.22

0.07

(40,42]

9

0.45

0.22

15.31

2.60

(42,44]

20

0.69

0.24

16.79

0.62

(44,46]

12

0.86

0.17

11.77

0.00

(46, $\infty$ )

12

1.00

0.14

9.93

0.43

$\sum$

70

1.00

70.00

3.72