Answer: 40% decrease.
Step-by-step explanation: To find the percent decrease we will be using the "Percent Decrease" equation.
change = percent change x actual
To find the change subtract 3.9 from 6.5, which is 2.6 kg, or 2.6 as the change.
2.6 = percent change x actual
The actual is 6.5, because the actual or original mass of the pumpkin was 6.5 kg.
2.6 = percent change x 6.5 (Solve for p, percent change.)
2.6 = p x 6.5
2.6/6.5 = p
0.4 = p
Now, to find the percent decrease multiply the decimal 0.4 by 100.
0.4 x 100 = 40, or 40%.