In: Statistics and Probability
a)
frequency distribution-
| class interval | frequency |
| 30-39 | 3 |
| 40-49 | 3 |
| 50-59 | 7 |
| 60-69 | 9 |
| 70-79 | 9 |
| 80-89 | 6 |
| 90-99 | 3 |
relative frequency distribution-
| class interval | frequency | relative frequency=fi/N |
| 30-39 | 3 | 0.075 |
| 40-49 | 3 | 0.075 |
| 50-59 | 7 | 0.175 |
| 60-69 | 9 | 0.225 |
| 70-79 | 9 | 0.225 |
| 80-89 | 6 | 0.150 |
| 90-99 | 3 | 0.0750 |
b)
| class interval | frequency | relative frequency=fi/N | cumulative frequency | cumulative relative frequnecy | ||
| 30-39 | 3 | 0.075 | 3 | 0.0750 | ||
| 40-49 | 3 | 0.075 | 6 | 0.1500 | ||
| 50-59 | 7 | 0.175 | 13 | 0.3250 | ||
| 60-69 | 9 | 0.225 | 22 | 0.5500 | ||
| 70-79 | 9 | 0.225 | 31 | 0.7750 | ||
| 80-89 | 6 | 0.150 | 37 | 0.9250 | ||
| 90-99 | 3 | 0.0750 | 40 | 1.0000 |
c)

d)

e)
proportion of the marks is less than or equal to 60 = 14/40 = 0.35
f) proportion of the marks is more than 70 = 17/40=0.425