What is the median of the values 120, 130, 150, and 170?

• A. 140
• B. 125
• C. 135
• D. 150

Answer: (A)

When the data set has an even number of values, the median is found by taking the average of the two middle numbers after the values are ordered. Here, the numbers in order are 120, 130, 150, 170. The two middle values are 130 and 150, so the median is (130 + 150) / 2 = 140. Therefore, the median is 140. The other options don’t fit because they aren’t the average of the two middle values for this set (150 is one middle value but not the average, while 125 and 135 lie outside the central pair).