Question: The following data are independent random samples of sales of the Nissan Pulsar model made in a joint venture of Nissan and Alfa Romeo. The data represent sales at dealerships before and after the announcement that the Pulsar model will no longer be made in Italy. Sales numbers are monthly.
Before: 329, 234, 423, 328, 400, 399, 326, 452, 541, 680, 456, 220
After: 212, 630, 276, 112, 872, 788, 345, 544, 110, 129, 776
Do you believe that the variance of the number of cars sold per month before the announcement is equal to the variance of the number of cars sold per month after the announcement?