Researchers were interested in the influence of yoga on reported stress levels in high school seniors. A sample of 29 high school seniors reported stress levels before (Time 1) and after (Time 2) a 30-minute yoga class. The mean difference value (x2−x1) was −0. 35, with a standard deviation of 1. 1. Calculate the lower boundary of the 95% confidence interval. Report your answer rounded to the nearest two decimal places.
A) -0. 46
B) -0. 82
C) -1. 01
D) -0. 68