In "Response time analysis" view, in the right rectangle, "Response time" and "Response time contribution" are exchanged for each other.
In the following example, there should be :
Response time 1.13 s
× Percentage of calls 69%
× Invocations per call 1x
= Response time contribution 0,78 s
Of the PurePaths you're looking at 69% of them call that downstream service. When it is called it takes on average 1.64 seconds. So the amount that overall is contributed to the upstream service response time calculated in this way is .69 * 1.64 which is 1.33 seconds. That's what the response time contribution there is measuring.