Question

question 1
5 points
the value of one score in a distribution is changed from x = 20 to x = 30. which measure(s) of central tendency is (are) certain to change
a mode
b median
c mean
d mean and median

Explanation:

The mode is the most frequently - occurring value and may not change if the changed score is not the mode. The median is the middle value when scores are ordered; if the position of the changed score doesn't affect the middle value(s), it won't change. The mean is calculated as $\frac{\sum_{i = 1}^{n}X_i}{n}$. Changing one score changes the sum $\sum_{i = 1}^{n}X_i$, thus the mean will change.

Answer:

C. Mean