Question: from an analysis of wind speed data hourly interval average...

From an analysis of wind speed data (hourly interval average, taken over a one year period), the Weibull parameters are determined to be lambda = 6 m/s and k = 2.08. Estimate the number of hours per year that the wind speed will be between 7 and 9 m/s during the year. (answer to 2 decimal places)