Sheridan Monograms sells stadium blankets that have been monogrammed with high school and university emblems. The blankets retail for $41 throughout the country to loyal alumni of over 4,200 schools. Sheridan’s variable costs are 43% of sales; fixed costs are $114,000 per month. Sheridan currently sells 122,000 blankets per year. If sales volume were to increase by 15%, by how much would operating income increase?