Use the cumulative frequencies to figure out what the individual frequencies would be. Check out the attached image for the table of x values with their corresponding frequency (f) values. Note how the partial sums add up to the cumulative frequency values.
Once you know the frequency f values, multiply each x and f pair together in each row. The column labeled "x*f" represents each product. Afterward, add up everything in the x*f column to get the final answer 6.8
