The total area under any curve representing the distribution of a variable equals 1. Explain why. Choose the correct answer below. OA. The total area under any curve representing the distribution of a variable does not always equals 1. The area under the standard normal curve does equal 1 but it varies by distribution. OB. The area under a curve representing the distribution of a variable is equal to 1 because the area under a standard normal curve is equal to 1 and it became accepted that the area under all density curves should also equal 1. OC. It is set to equal 1 to make calculations easier but it could have been set at any amount. OD. Percentages for a variable are equal to areas under its density curve expressed as a percentage. An area of 1 is 100% when expressed as a percentage and 100% represents the entirety of the area.