For this question, we will be doing proportions, and from there we can solve for x.
[tex] \frac{8}{24} = \frac{x}{60} [/tex]
Cross multiply to get [tex]24x=480[/tex]
Then divide by 24 on each side, and your answer should be [tex]x=20[/tex]
In short, Natalie needs 20 cups of flour for 60 muffins.