Calculating The Nth Mode on Two Interrelated Data Sets

You could generate a histogram of sizes:

	A	B	C	D	E	F
1	Width	Depth	Helper	Count
2	55	70	55|70	2		C2: =A2 & "|" & B2
3	50	70	50|70	2		D2: =COUNTIF($C$2:$C$196, C2)
4	50	62	50|62	1
5	50	60	50|60	3
6	50	55	50|55	23
7	50	55	50|55	23
8	50	55	50|55	23
9	50	55	50|55	23
10	50	80	50|80	1
11	55	70	55|70	2
12	50	55	50|55	23
13	50	55	50|55	23
14	50	55	50|55	23
15	50	55	50|55	23
16	50	55	50|55	23
17	50	55	50|55	23
18	45	60	45|60	6
19	50	65	50|65	12
20	50	65	50|65	12
21	50	65	50|65	12
22	50	65	50|65	12
23	50	65	50|65	12

Then copy the formula and replace with values, sort descending by col C, and remove duplicates:

	A	B	C	D
1	Width	Depth	Helper	Count
2	45	55	45|55	43
3	45	65	45|65	40
4	50	55	50|55	23
5	50	65	50|65	12
6	45	64	45|64	8
7	45	58	45|58	7
8	45	60	45|60	6
9	45	57	45|57	5
10	45	59	45|59	4
11	50	60	50|60	3
12	50	64	50|64	3
13	55	70	55|70	2
14	50	70	50|70	2
15	45	63	45|63	2
16	55	55	55|55	2
17	60	55	60|55	2
18	45	62	45|62	2
19	50	75	50|75	2
20	50	62	50|62	1
21	50	80	50|80	1
22	50	67	50|67	1
23	50	63	50|63	1
24	50	61	50|61	1
25	50	59	50|59	1
26	50	57	50|57	1
27	55	51	55|51	1
28	55	65	55|65	1
29	45	78	45|78	1
30	45	77	45|77	1
31	55	45	55|45	1
32	65	55	65|55	1
33	50	54	50|54	1
34	45	73	45|73	1
35	60	65	60|65	1
36	55	58	55|58	1
37	45	70	45|70	1
38	50	72	50|72	1
39	45	79	45|79	1
40	45	67	45|67	1
41	40	55	40|55	1
42	45	72	45|72	1
43	45	61	45|61	1
44	58	55	58|55	1
45	55	48	55|48	1
46	50	53	50|53	1

You're welcome.