Question

In a bolt-manufacturing factory, it is estimated that 6% of the bolts being manufactured will be defective, with a 3% margin of error. Choose the statement that correctly describes the confidence interval.

A. The percentage of defective bolts is 6% or more.
B. The percentage of defective bolts is 6% or less.
C. The percentage of defective bolts is between 3% and 6%.
D. The percentage of defective bolts is between 3% and 9%.

Answer 1

D

Explanation:

A margin of error provides information on the percentage points ones results will differ from the real value.

If margin of error is 3% and estimated value is 6%, it means that the confidence interval would be within ±3 of the estimated value.

So, the confidence interval would be between 3% (6% - 3%) and 9% (6% + 3%)