Chelsea receives a commission of 2.7% on her monthly sales up to $3,700. The rate then increases to 4.3% on the next $7,100, and the top rate of 7.5% applies to any further sales. During April, Chelsea's sales were $7,151 and sales returns were $1,926. a) Calculate Chelsea's commission for April. $Correct b) Calculate her average hourly rate if she worked 23 hours during April.