Answer:
![\boxed{(2)/(7)}](https://img.qammunity.org/2021/formulas/mathematics/middle-school/a6998n4qmz3histi0zt6ff6bkileia6nbp.png)
Explanation:
Part 1: Finding out total number of marbles
To start, we need to find out how many marbles are in the bag.
marbles
Part 2: Removing blue marble and finding probability
After removing the blue marble and not replacing it, we can then infer that we have 14 marbles remaining.
If we have 4 red marbles in the bag, simply find the ratio of red marbles to the total marbles.
or a 28.57% chance of occurrence.