Answer:
0.5172 = 51.72% probability a blue poker chip was transferred from box A to box B, given that the coin just chosen from box B is red
Step-by-step explanation:
Conditional Probability
We use the conditional probability formula to solve this question. It is

In which
P(B|A) is the probability of event B happening, given that A happened.
is the probability of both A and B happening.
P(A) is the probability of A happening.
In this question:
Event A: Coin chosen from box B is red.
Event B: Blue poker chip transferred.
Probability of choosing a red coin:
7/10 of 4/9(red coin from box A)
6/10 of 5/9(blue coin from box A). So

Blue chip transferred, red coin chosen:
6/10 of 5/9. So

What is the probability a blue poker chip was transferred from box A to box B, given that the coin just chosen from box B is red?

0.5172 = 51.72% probability a blue poker chip was transferred from box A to box B, given that the coin just chosen from box B is red