Question

n a physics lab, a student was measuring the amount of time for a ball to drop to the ground. She repeated the experiment six times, using the same ball dropped from the same distance each time. Here are her measurements (in seconds):

3.45

3.41

3.47

3.93

3.38

3.41

She concluded that the measurement 3.93 seconds was an outlier. When doing her analysis, what should she do about the outlier? Explain your reasoning.

The score for this question will show zero points until graded by the instructor.

Answer 1

Suppose, random variable X denotes the amount of time required to drop to the ground.

We now estimate values of and using sample values.

Clearly, the value 3.93 seems to be an outlier (by comparing with other values). Without this value we perform our computations.

Now 3-sigma control limit is given by i.e. (3.317, 3.531).

The value 3.93 does not lie in the 3-sigma limit. So, we can justifiably reject this particular observation.