Getting an average of the data from a percentile.

[LEFROGUE]

Hello,

I would like to get the bid cost for each percentile of search volume (What is the 70th percentile bid cost for search volume? ( At 3325.8 search volume what is the bid cost?). Is there a way to use a formula for instead of doing it step by step like below. Have 5k lines of data to work through.

Book2
	A	B	C
19	Search Volume	Bid Cost	Cumulative Search Volume
20	50	£ -	50
21	670	£ -	720
22	234	£ -	954
23	867	£ -	1,821
24	354	£ -	2,175
25	68	£ 0.13	2,243
26	50	£ 0.21	2,293
27	550	£ 0.47	2,843
28	340	£ 0.47	3,183
29	357	£ 1.00	3,540
30	778	£ 2.40	4,318
31
32	Search vol percentile	Percentile
33	766.8	10
34	1300.8	20
35	2033.4	30
36	2229.4	40
37	2293	50
38	2911	60
39	3325.8	70
40	4006.8	80
Sheet1

Cell Formulas
Range	Formula
B20:B30	B20	=C2
C20:C30	C20	=SUM($A$20:A20)
A33	A33	=PERCENTILE.EXC($G$21:$G$31,0.1)
A34	A34	=PERCENTILE.EXC($G$21:$G$31,0.2)
A35	A35	=PERCENTILE.EXC($G$21:$G$31,0.3)
A36	A36	=PERCENTILE.EXC($G$21:$G$31,0.4)
A37	A37	=PERCENTILE.EXC($G$21:$G$31,0.5)
A38	A38	=PERCENTILE.EXC($G$21:$G$31,0.6)
A39	A39	=PERCENTILE.EXC($G$21:$G$31,0.7)
A40	A40	=PERCENTILE.EXC($G$21:$G$31,0.8)

Grateful for any help. Thankyou.