A fitness center piloted two new programs to help people reduce stress levels and maintain a healthy lifestyle. After one month, 112 of the 125 people who volunteered for a program in mindfulness reported a reduction in stress levels, and 110 of the 135 people who volunteered for a yoga program reported a reduction in stress levels. The fitness center wants to investigate whether there is a significant difference between the proportions of all people in the two programs who would report reductions in stress levels. Have the conditions for inference been met? A
No, because the samples were not selected or assigned using a random method.
B
No, because the sizes of the samples are too large compared to the size of the population.
C
No, because the normality of the sampling distribution cannot be assumed; the number of people who did not experience stress relief is not large enough.
D
Yes, because all conditions for making statistical inference have been met.