If the cost of the ice cream custard is directly proportional to its weight in ounces, we can express this relationship using the equation:
\[ Y = kx \]
where:
- \( Y \) is the cost,
- \( x \) is the weight in ounces,
- \( k \) is the constant of proportionality (the cost per ounce).
To complete the equation, you would need to know the value of \( k \). For example, if the cost is $2 per ounce, the equation would be:
\[ Y = 2x \]
Without a specific value for \( k \), the equation remains incomplete as:
\[ Y = kx \]
You would replace \( k \) with the actual cost per ounce when you have that information.