A scientist investigated the effect of cross-fertilization on the heights of plants. In one study, the scientist planted 15 pairs of a species of plant. Each pair consisted of one cross-fertilized plant and one self-fertilized plant grown in the same pot. The table available below gives the height differences, in eighths of an inch, for the 15 pairs. Each difference is obtained by subtracting the height of the self-fertilized plant from that of the cross-fertilized plant. Use the paired t-interval procedure to determine a 95% confidence interval for the difference between the mean heights of cross-fertilized and self-fertilized plants. Interpret the result. (Note: d=21.87 and sd​=36.53.)