To find the total amount of all four ingredients in Hayley's trail mix, we will add them together.
- Cereal: 2 1/2 cups
- Nuts: 3/4 cup
- Coconut: 1/4 cup
- Chocolate chips: 1 1/4 cups
Let's convert all the mixed numbers to improper fractions for easier addition:
- 2 1/2 cups = \( \frac{5}{2} \) cups
- 3/4 cup = \( \frac{3}{4} \) cups
- 1/4 cup = \( \frac{1}{4} \) cups
- 1 1/4 cups = \( \frac{5}{4} \) cups
Now, let's find a common denominator to add these fractions. The common denominator for 2 and 4 is 4. We will convert \( \frac{5}{2} \) into fourths:
\[ \frac{5}{2} = \frac{5 \times 2}{2 \times 2} = \frac{10}{4} \]
Now we can add all the fractions together:
\[ \frac{10}{4} + \frac{3}{4} + \frac{1}{4} + \frac{5}{4} \]
Adding the numerators:
\[ 10 + 3 + 1 + 5 = 19 \]
So,
\[ \frac{19}{4} \]
Now, we will convert \( \frac{19}{4} \) back into a mixed number:
\[ \frac{19}{4} = 4 \frac{3}{4} \]
Thus, the total amount of all four ingredients is:
4 3/4 cups.
The correct answer is D. 4 3/4 cups.