class

mean

N

standard deviation

class one

7.2500

16

1.06458

class two

8.6750

20

0.94972

class three

7.8000

15

1.34695

class four

7.9333

15

1.61319

class five

8.7727

11

1.21169

class six

8.0938

16

1.08349

class seven

8.0625

16

1.01448

class eight

8.5556

9

1.10240

total

8.1144

118

1.24106