Question

Determine whether the results appear to have statistical significance, and also determine whether the results have practical significance:

Most people have IQ scores between 70 and 130. For $32, you can purchase a computer program from Highiqpro.com that is claimed to increase your IQ score by 10 to 20 points. The program claims to be "the only proven IQ increasing software in the brain training market," but the author of your text could find no data supporting that claim, so let's suppose that these results were obtained: In a study of 12 subjects using the program, the average increase in IQ is 3 IQ points. There is a 25% chance of getting such results if the program has no effect.

A. Statistically significant, practically significant
B. Statistically significant, not practically significant
C. Not statistically significant, practically significant
D. Not statistically significant, not practically significant

Answer 1

The average increase in IQ points of 3 and the p-value of 25% suggest that the program's effect is neither statistically significant nor practically significant, leading to the answer option D.

Step-by-step explanation:

To determine whether the increase in IQ scores after using the Highiqpro.com computer program is statistically significant, we look at the p-value. The p-value indicates a 25% chance of getting an average increase of 3 IQ points if the program has no effect.

Since commonly used thresholds for statistical significance are 0.05 (5%) or 0.01 (1%), a p-value of 0.25 (25%) is much higher and therefore not statistically significant. Hence, we cannot reject the null hypothesis, which would state that the program has no effect on IQ scores.

As for practical significance, an increase of 3 IQ points is quite small, especially when considering that the program claims an increase of 10 to 20 points. Given that most people have IQ scores between 70 and 130, a change of 3 points is unlikely to reflect a meaningful impact on someone's cognitive abilities or daily functioning. Therefore, the results lack practical significance as well.

The correct answer is D. Not statistically significant, not practically significant.