First answer gets 5 stars and thanks

option d

Step-by-step explanation:

Let that number be n ,

Then ,

=> 0.8 + n = 4.5

I think its the last option

Step-by-step explanation:

As the sentence said increased by a number it means addition. And as the sentence said 0.8 increased by a number it will be 0.8 + n = 4.5.

Hope this helps!!