We calculate DPM using the below formula:
Sample Size is calculated using the below formula:
Where CI is the confidence Interval in decimal format. If the Confidence Interval is ±4% then use 0.04.
p is Percentage of the sample picking a choice, expressed in decimal.
Sample Size Calculation: For a Confidence Level of 95%, which is the most commonly used Confidence Level by researchers, we use a p = 0.50 and Z value = 1.96. A confidence level of 95% means that you are 95% certain about the outcome.