You subtract the least value from the greatest value.
To find the mean you add all of the numbers then divided them by how many numbers there are. The mode is the number that pops up the most. The meadian is to add up all of the numbers and divide by the number of numbers in the data set. The median is the central number of a data set. Arrange data points from smallest to largest and locate the central number. This is the median.
The events 'select a plain pencil' and 'select a color pencil' are independent. therefore the probability of both occurring is the product of their probabilities: The answer is 3/20 or 0.15.
