Assuming a 90% confidence level, the margin of error is approximately?

  0.3

Step-by-step explanation:

The margin of error is calculated as ...

  (standard deviation)/√(sample size) × (z*-score)

where the z*-score is chosen based on the desired confidence level.

Here, you have ...

Putting these values in the above expression for margin of error gives ...

  2.7/15·1.645 = 0.2961 ≈ 0.3

b. f(x) = –√x + 3this is the correct answer

the answer on e2020 was d.