Directions: Attempt the Step 1 question(s) which are shown below, pick one answer from the multiple choices below and then check your correct answer by clicking on get answer button.
Question:
A total of 1000 individuals with a body mass index (BMI) greater than 30 are recruited for a multicenter study focused on testing methods for controlling obesity. Study participants are randomly assigned to one of two groups: a treatment group, which is enrolled in a mentored weight loss program, or a control group, which is shown an educational video and given instructions on wight loss methods. Both groups have the same average weight at the start of the study. The weight of all study participants is assessed at the end of a 6-month trial, and the average weights of treatment and control groups are compared. Before formal statistical analyses are conducted, however, the researchers examine the general properties of the resulting data. This examination reveals the following results:
95% of Sample in This Range
| Low | High | |
| Control group | 154 lb | 213 lb |
| Treatment group | 133 lb | 192 lb |
Using this information, the researchers decide to make some determinations about the standard deviation and the variance for the two groups. An examination of the interval containing 95% of each group suggests which of the following?
A. Definitive conclusions about the standard deviations and the variances cannot be made without additional data
B. The standard deviations and the variances of both samples are different
C. The standard deviations and the variances of both samples are equal
D. The standard deviation of both samples is equal, but the variances are different
E. The standard deviations of both samples are different, but the variances are equal
