Diagram shows a section of a bridge between the points a and k. the length of line segment is 640 meters. ∆abc, ∆cdf, and ∆fjk are similar, and 2ac = cf = 2fk. the first pillar, , is 20 meters tall.
the area of ∆cdf is square meters.

Select the correct answer from each drop-down menu. james needs to clock a minimum of 9 hours per day at work. the data set records his daily work hours, which vary between 9 hours and 12 hours, for a certain number of days. {9, 9.5, 10, 10.5, 10.5, 11, 11, 11.5, 11.5, 11.5, 12, 12}. the median number of hours james worked is . the skew of the distribution is