5. Does the frequency distribution given appear to be normal?
Years of service Frequency
1-5. 5
6-10 20
11-15. 25
16-20. 18
21-25. 5
26-30. 1
Yes, there is not symmetry.
Control
Yes, the frequencies are roughly symmetrical around the maximum.
No, the frequencies increase, reach a maximum, then decrease.
No, there is not a concentration of frequencies in the middle.