class

mean

N

standard deviation

class one

8.5938

16

0.77392

class two

9.2500

20

1.10322

class three

8.7500

15

1.49404

class four

8.4167

15

1.45365

class five

8.9773

11

1.09233

class six

8.2813

16

1.10633

class seven

8.2031

16

1.11512

class eight

9.0278

9

1.21478

total

8.6758

118

1.20421