Question

Do you think that you could help me with this question, ​please?

Answer 1

The price went down, basically all you do is take 1.25 - 3.125 then + .625 then +1.5 and you're left with -.3125.

Answer 2

Add up the weekly changes in the price:
= 1.25 - 3.125 + 0.625 + 1.5 =  0.25

So there was an increase of 0.25 dollars on 1 gram of gold