What data type is used to represent positive or negative decimal numbers like 12.3864?

The appropriate data type used to represent positive or negative decimal numbers like 12.3864 is a "Double." This data type specifically allows for the representation of decimal values with high precision, accommodating a wider range of fractional values compared to other types.

While a Float can also represent decimals, it has less precision than a Double. This means that for applications requiring a greater degree of accuracy, especially with larger or more precise numbers, the Double type is preferred. An Integer, on the other hand, is used solely for whole numbers without any decimal component, making it unsuitable for decimal representation. Lastly, a Character data type is used for storing single characters, which is irrelevant in this context because it does not represent numerical values at all.

Using the Double data type ensures that calculations involving decimal numbers can be performed with the necessary accuracy, which is especially important in financial applications, scientific computations, or anywhere that precise decimal representation is critical.