To create a function rule \( f \) that gives the total cost of apples in terms of the number of pounds \( x \), we start with the given cost, which is $1.25 for 6 pounds.
First, we determine the cost per pound. The cost per pound can be calculated by dividing the total cost by the number of pounds:
\[ \text{Cost per pound} = \frac{$1.25}{6 \text{ pounds}} \approx 0.2083 \text{ dollars per pound} \]
Now we can express the function \( f(x) \), where \( x \) is the number of pounds, as follows:
\[ f(x) = \text{cost per pound} \times x = \left(\frac{1.25}{6}\right) \times x \]
Simplifying the function gives us:
\[ f(x) = \frac{1.25}{6}x \]
For clarity, you could also write it as:
\[ f(x) = 0.2083x \]
So the function \( f \) can be expressed as:
\[ \boxed{f(x) = \frac{1.25}{6} x} \]
or numerically approximated to:
\[ \boxed{f(x) \approx 0.2083x} \]
This function will provide the total cost of apples for any input value of \( x \) (the number of pounds).