class

mean

N

standard deviation

class one

7.6563

16

1.14741

class two

8.6250

20

1.18701

class three

7.9444

15

1.36810

class four

7.9444

15

1.08501

class five

8.3333

11

1.23603

class six

7.8125

16

0.67185

class seven

8.0208

16

0.95622

class eight

8.2407

9

0.97222

total

8.0720

118

1.10950