Given the weight of a package, return the shipping charge based on the following rates. If the package weight is 2 pounds or less, the rate is $1.1; if the package weight is over 2 pounds, but not more than 6 pounds, the rate is $2.2; if the package weight is over 6 pounds, but not more than 10 pounds, the rate is $3.7; if the package weights more than 10 pounds, the rate is $3.8.