bicycle shop plans to offer 2 specially priced​ children's models at a sidewalk sale. The basic model will return an income of ​$110 and the deluxe model ​$120. Past experience indicates that sales of the basic model will have a mean of 5.8 bikes with a standard deviation of 1.1​, and sales of the deluxe model will have a mean of 3.1 bikes with a standard deviation of 0.7 bikes. The cost of setting up for the sidewalk sale is ​$300. what is standard deviation of the net income ​