Before 1983, pennies were 97% copper and 3% zinc, but after 1983 they are 3% copper and

Question:

Before 1983, pennies were 97% copper and 3% zinc, but after 1983 they are 3% copper and 97% zinc. Using the data from Data Set 40 “Coin Weights” we get the statistics shown below. Use a 0.05 significance level to test the claim that the variation of weights before 1983 is greater than the variation of weights after 1983. If that claim is supported, what is an advantage of the change?