Why is there no commutative property for subtraction and division

Ihave a 69 and an 82. the 69 is worth 40% of my grade and the 82 is worth 15%. can someone tell me my current average grade.

What is the greater volume 72 quarts or 23 gallons

The fraction of defective integrated circuits produced in a photolithography process is being studied. a random sample of 300 circuits is tested, revealing 17 defectives. (a) calculate a 95% two-sided confidence interval on the fraction of defective circuits produced by this particular tool. round the answers to 4 decimal places. less-than-or-equal-to p less-than-or-equal-to (b) calculate a 95% upper confidence bound on the fraction of defective circuits. round the answer to 4 decimal places. p less-than-or-equal-to