The amount of milk produced by dairy cows depends on a number of factors, including average temperature and rainfall. A large dairy co-op forecasts that production of milk next month in its northern region will be normally distributed with a mean of 100,000 gallons and a standard deviation of 40,000 gallons. Production next month in its southern region is forecasted to be normally distributed with a mean of 80,000 and a standard deviation of 30,000. The correlation between the two regions is 0.4. What is the coefficient of variation for total milk production across the two regions?