Can someone help me please? I am struggling and I would be so happy if any of you helped me. Can someone help me out with this problem please?

The symbol means "plus minus".

Writing is the same as saying

The lower bound, or left endpoint, is 1.5 - 0.85 = 0.65

The upper bound, or right endpoint, is 1.5 + 0.85 = 2.35

Based on what you have, it looks like you probably followed those steps. However, you have the items in the wrong order. You should have 0.65 listed first and 2.35 listed last. Also, you need to have "or equal to" as part of the inequality sign.

So you should have

As for your graph, you have the endpoints in the wrong spot.

The left endpoint should be between the 0.6 and 0.7 to indicate 0.65

The right endpoint should be between 2.3 and 2.4 to indicate 2.35

See the diagram below.