Final answer:
Nina initially baked 500 cookies in total for the bake sale, of which she sold 475 cookies, representing 95% of her initial batch.
Step-by-step explanation:
If Nina sold 95% of her cookies and that amounted to 475 cookies, we want to find out how many cookies she baked in total. To do this, we set up a proportion where 95% (or 0.95 in decimal form) times the total number of cookies equals 475.
The equation is: 0.95 × total cookies = 475. To solve for the total number of cookies, we divide both sides of the equation by 0.95:
total cookies = 475 ÷ 0.95
total cookies = 500
Therefore, Nina baked 500 cookies altogether before the bake sale.