Question

The makers of a popular brand of laundry detergent have discovered a new secret ingredient that they believe will boost the cleaning power of their detergent. The new ingredient is expensive, and if they use it, they would have to increase the retail price of the detergent (and they worry that the price increase will cause them to lose customers). However, they believe that if the improved detergent gets clothes drastically cleaner, customers will recognize that it is worth the extra cost. They conduct an experiment to compare the performance of the new and old formulas at removing grass stains, red wine, and chocolate from white t-shirts. Each cleaned shirt was rated on a scale from 1 (stain did not get removed) to 10 (no evidence of the stain) by trained experts. They compared the average rating for the new and old formulas. Suppose, at the 5% significance level, they find that the new formula cleaned the shirts significantly better than the old formula, with a p-value of 0.046. Interpret the p-value, in terms of the probability of the results happening by random chance, in this context.

Answer 1

Answer:

The p-value is of 0.046 < 0.05, which means that there is a low probability of the results happening by random chance, and thus there is significant evidence to conclude that the new formula cleaned the shirts significantly better than the old formula.

Step-by-step explanation:

If the p-value is less than the significance level, it means that there is a low probability of the results happening by random chance.

In this question:

The p-value is of 0.046 < 0.05, which means that there is a low probability of the results happening by random chance, and thus there is significant evidence to conclude that the new formula cleaned the shirts significantly better than the old formula.