"construct a frequency distribution" just means do the following:

Step1: Put the data into logical groups

Step2: Count the number of data points in each group.

You are told to use 4 groups, with the first one having a lower limit of 60.

Sensible group choices would be:

Group1: Score 60-69

Group2: Score 70-79

Group3: Score 80-89

Group4: Score 90-99

For each group, the frequency is just the number of scores that were in that group.

Code:

Score | Frequency
---------------------
60-69 | 3
70-79 |
80-89 |
90-99 |