We can start by creating a table to organize the information:
Likes Chocolate (c) Does Not Like Chocolate (~c) Total
Likes Sprinkles (s) 0.25 0.40
Does Not Like Sprinkles (~s) 0.60
Total 0.70 0.30 1.00
We are given that 40% of friends like sprinkles, so we can fill in that cell of the table. We are also given that 25% of friends who like chocolate also like sprinkles, so we can fill in the cell for likes chocolate and likes sprinkles as 0.25.
To find the proportion of friends who like sprinkles and chocolate, we need to divide the number of friends who like both by the total number of friends who like sprinkles:
proportion = likes chocolate and sprinkles / likes sprinkles
proportion = 0.25 / 0.40
proportion = 0.625
So, approximately 62.5% of friends who like sprinkles also like chocolate.