Answer:
A. Increase the level of confidence
Step-by-step explanation:
The margin of error is given by:
The margin of error is:
[tex]M = \frac{Ts}{\sqrt{n}}[/tex]
In which T is related to the level of confidence(the higher the level of confidence, the higher T is), s is the standard deviation of the sample and n is the size of the sample.
Increase the width:
That is, increasing the margin of error, as the width is twice the margin of error, the possible options are:
Increase T -> increase confidence level.
Increase s -> Increase the standard deviation of the sample.
Decrease n -> Decrease the sample size.
Thus, the correct answer is given by option A.
