Answer:
- 11000: 31.5 °F
- 15000: 17.5 °F
- 18000: 7 °F
Explanation:
When you have repetitive calculations to do, it is often convenient to let a calculator or spreadsheet do them for you.
Basically, put the value of "a" into the formula and do the arithmetic.
Example: for 11000 ft, -0.0035·11000 +70 = -38.5 +70 = 31.5