How does randomization in a clinical trial controls confounding variables such as age of the participants or pre-existing conditions?

Don't know how to find x given these segment lengths

In the diagram, points d and e are marked by drawing arcs of equal size centered at b such that the arcs intersect ba and bc. then, intersecting arcs of equal size are drawn centered at points d and e. point p is located at the intersection of these arcs. based on this construction, m , and m

Amajor grocery store chain is trying to cut down on waste. currently, they get peaches from two different distributors, whole fruits and green grocer. out of a two large shipments, the manager randomly selects items from both suppliers and counts the number of items that are not sell-able due to bruising, disease or other problems. she then makes a confidence interval. is there a significant difference in the quality of the peaches between the two distributors? 95% ci for pw-pg: (0.064, 0.156)