A mean is an arithmetic average of a set of observations. The correct option is A.
A mean is an arithmetic average of a set of observations. it is given by the formula,
Mean = (Sum of observations)/Number of observations
Since the median is the middle value of the given data set, therefore, the median will not be changed for the given data set. But since the mean is the arithmetic average, therefore, the $100 gift will increase the mean value of the prizes.
Hence, the correct option is A.
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