6. Consider the data summarized in the R output below. Find the missing count (i.e., the value of in the last row). x count cumpct [0,5) ? 8.00 [5,10) 4 24.00 [10,15) ? 52.00 [15,20) x 100.00 (a) (b) (c) (d) (e) 25 12 8 7 5