10.51 Six rockets, nominally with a range of 2,500 meters, were stored for some time and then tested. The ranges found in the tests were 2,490, 2,510, 2,360, 2,410, 2,300, and 2,440. Another group of six rockets, of the same type, was stored for the same length of time but in a different manner. The ranges for these six were 2,410, 2,500, 2,360, 2,290, 2,310, and 2,340. Do the two storage methods produce significantly different mean ranges? Use and assume range measurements to be approximately normally distributed with the same variance for each manner of storage.