Which measure of central tendency is influenced by extreme scores in a data set?

The mean is the measure of central tendency that is influenced by extreme scores, also known as outliers, in a data set. This is because the mean is calculated by adding all values together and dividing by the number of values, meaning that each score has an equal impact on the final average. When extremely high or low scores are present, they can disproportionately affect the mean, pulling it higher or lower than the central point of the majority of the data.

In contrast, the median is the middle value when data is ordered, making it resistant to extreme scores. The mode, being the most frequently occurring value in a set, does not take all scores into account, so it remains unaffected by outliers. The standard deviation measures the amount of variation or dispersion in a set of values, but it also does not serve as a measure of central tendency and does not represent a central value itself. Thus, the mean is the correct answer as it is directly affected by extreme values in the data set.