Which function in the Summarize tool can only be used with numeric data types?

The function that can only be used with numeric data types in the Summarize tool is the "Sum" function. This function is specifically designed to calculate the total of numeric values in a given field. It accumulates the values and provides a single total sum as the output, which is meaningful and applicable only to numeric data.

While the "Max" function can be used with numeric data to find the highest value, it can also be applied to other data types such as text, where it determines the maximum value based on alphabetical order. The "Count" function, meanwhile, counts records regardless of data type, and the "First" function merely retrieves the first value in a sorted list without the need for numerical data.

Therefore, the Sum function distinctively requires numeric data to perform its operation, making it the only option that is exclusive to numeric data types.