Data on the modulus of elasticity obtained 1 minute after loading in a certain configuration and 4 weeks after loading for the same lumber specimens is presented here.

Observation	1 min	4 weeks	Difference
1	10,779	9,875	904
2	16,620	13,250	3370
3	17,300	14,720	2580
4	15,830	12,713	3117
5	12,970	10,120	2850
6	17,260	14,570	2690
7	13,400	11,220	2180
8	13,099	11,858	1241
9	13,630	11,420	2210
10	13,260	10,910	2350
11	14,370	12,110	2260
12	11,577	8,819	2758
13	15,470	12,590	2880
14	17,840	15,090	2750
15	14,070	10,550	3520
16	14,190	12,157	2033

Calculate and interpret an upper confidence bound for the true average difference between 1-minute modulus and 4-week modulus; first check the plausibility of any necessary assumptions. (Use = 0.05. Round your answer to the nearest whole number.) Upper Confidence Bound: