Lu Cho has health insurance that pays 90 percent of covered charges after a $1,000 deductible. There is a stop-loss provision of $10,000. So far this year, Lu has paid $7,900 in deductibles and copayments. Lu received a new statement for $4,000 in medical charges. How much will Lu have to pay?

i believe it’s b because the rest don’t make sense

hi : ) i found this so i hope this !

"we first find value of tax in dollars.

the difference between the two prices   is: 23. 54 - 22 = 1.54

therefore the sales tax in dollars is 1.54

the tax % will be   (amount of tax / original cost price ) × 100

(1.54 / 22) × 100  → (0.07) × 100 =   7

so the tax rate is 7%

we can double check the answer.

7 % of 22   → (7/100) × 22 → 0.07 × 22 = 1.54

22 + 1.54 = 23.54"

answer; by looking at total product,marginal product,and changes in both after changes in inputs