Pls help im in the test i’ll give 50 points

On a piece of paper graph f(x)=5•(0.4)^x

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

In a survey of 1015 adults, a polling agency asked, "when you retire, do you think you will have enough money to live comfortably or not. of the 1015 surveyed, 534 stated that they were worried about having enough money to live comfortably in retirement. construct a 90% confidence interval for the proportion of adults who are worried about having enough money to live comfortably in retirement.