60

6.0

12.0

5.0

1

5.0

4.0

2.0

5.0

12.0

6.0

123

19

6.4737

2

7.0

11.0

3

2.0

13.0

3.0

4.0

15.0

2.0

5.0

4.0

70

1

13.0

3.0

1.0

14.0

5.0

2.0

4.0

2

9.0

13.0

6.0

156

21

7.4286

9.0

4.0

7.0

5.0

3

2.0

6.0

15.0

8.0

13.0

5.0

12.0

X i ...

180

213

253

N i

29

23

29

X ¯ i ...

6.2069

9.2069

8.7241

X .. j .

178

248

220

N i

26

26

29

X ¯ .. j .

6.8462

9.8462

7.5862