Answer:
32.8 kg
Step-by-step explanation:
You want the new mean if 10 measurements have a mean of 33.2 kg, and one value is reduced by 4 kg.
The mean is the sum divided by the number of measurements. If the mean of 10 measurements is 33.2, their sum is 332. If one is reduced by 4 kg, the sum is reduced to 328 kg. The new mean will be ...
328 kg/10 = 32.8 kg . . . . . the new mean
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Additional comment
The effect on the mean is the change in the value divided by the number of contributors to the mean. One value decreasing by 4 kg makes the mean of 10 measurements decrease by (4 kg)/10 = 0.4 kg. The new mean is 33.2 -0.4 = 32.8.
