In a batch of 890 calculators, 12 were found to be defective. what is the probability that a calculator chosen at random will be defective? write the probability as a percent. round to the nearest tenth of a percent if necessary. 1.8% 98.7% 74% 1.3%

  answer:

  write 548 as 500 + 40 + 8. multiply each addend by 5. then add the three products to get 2,740.

"standard form:

3x2 + 14x − 10 = 0

solutions based on quadratic formula:

x1   = −14 − √ 142 − 4×3×(−10) /   2×3   = −14 − 2 × √ 79 /   6   ≈ −5.296

x2   = −14 + √ 142 − 4×3×(−10) /   2×3   = −14 + 2 × √ 79 /   6   ≈ 0.629