Three Defective Electric Toothbrushes Were Accidentally Shipped to a Drugstore

question 110

Multiple Choice

Three defective electric toothbrushes were accidentally shipped to a drugstore by the manufacturer along with 17 non-defective ones. What is the probability that the first two electric toothbrushes sold will be returned to the drugstore because they are defective?

• A) 3/20 or 0.15
• B) 3/17 or 0.176
• C) 1/4 or 0.25
• D) 3/190 or 0.01579

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Definitions:

Degrees of Freedom

The number of independent values or quantities which can be assigned to a statistical distribution or a statistical calculation.

Sample Size

The number of observations or data points that make up a sample.

Level of Significance

The probability of rejecting the null hypothesis in a statistical test when it is actually true; a measure of how unlikely results are due to chance.

Degrees of Freedom

The amount of free variables or measures that may change within an analysis while still adhering to all limitations.