Question: Wind Speeds. The average wind speed in Casper, Wyoming, has been found to 12.7 miles per hour, and in Phoenix, Arizona, it is 6.2 miles per hour. To test the relationship between the averages, the average wind speed was calculated for a sample of 31 days for each city. The results are reported below. Is there sufficient evidence ata= 0.05 to conclude that the average wind speed is greater in Casper than in Phoenix?