Someone please help me on this I'm unsure if my answer is correct

Estimate each quotient. show the compatible numbers you use. 0.00438 ÷ 0.00072

Pyotr tchaikovsky sporting goods operates on a 45% overhead based on the selling price, which results in an overhead of $65.34 on the newest version of an air hockey game set. if the air hockey game set costs pyotr tchaikovsky sports $49.32, find the selling price, the markup, and the net profit.

Determine domain and range, largest open interval, and intervals which function is continuous.