Q16BSC Statistical Significance and Pra... [FREE SOLUTION]

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Chapter 1: Q16BSC (page 1)

Statistical Significance and Practical Significance. In Exercises 13鈥�16, determine whether the results appear to have statistical significance, and also determine whether the results appear to have practical significance.
IQ Scores Most people have IQ scores between 70 and 130. For $39.99, you can purchase a PC or Mac program from HighIQPro that is claimed to increase your IQ score by 10 to 20 points. The program claims to be 鈥渢he only proven IQ increasing software in the brain training market,鈥� but the author of your text could find no data supporting that claim, so let鈥檚 suppose that these results were obtained: In a study of 12 subjects using the program, the average increase in IQ score is 3 IQ points. There is a 25% chance of getting such results if the program has no effect.

Short Answer

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The results seem to neither have statistical significance nor practical significance.

Step by step solution

Given information

Claim for the program: The IQ scores increase by 10 to 20 points after its use.

The number of subjects in the study is 12. The average increase in IQ score is 3 points after using the program. There is a 25% chance to obtain this result if the program is assumed to have no effect.

Explanation for statistical significance

Statistical significance is established under the assumption that the program has no effect.If the chances of getting the results are unlikely under this condition, then the result is said to be statistically significant.

In this case, the chances of obtaining the given results, an increase of 3 IQ points post-program are 25%.

The value of 25% implies that the results are not rare, and hence, it can be concluded that the program has no statistically significant effect.

Explanation for practical significance

Practical significance describes the meaningfulness of the results.

The increase in IQ by 3 points implies that the program does not have any practical significance compared to the claim of a 10 to 20 point increase in IQ scores.

Thus, the results do not hold enough practical significance.