Praxis Core Academic Skills for Educators: Mathematics (5733)Statistics and ProbabilityEasy
A market researcher is analyzing the number of daily visitors to a new website for the first week: 150, 165, 140, 170, 155, 160, 180. What is the median number of daily visitors?
- A170
- B155
- C165
- D160
Show answer & explanationAnswer & explanation
Correct answer: D. 160
To find the median, first arrange the data in ascending order: 140, 150, 155, 160, 165, 170, 180. Since there are 7 data points (an odd number), the median is the middle value, which is the 4th value: 160.
Why the other options are wrong
- A. This is the sixth value in the ordered list, not the median.
- B. This is the third value in the ordered list, not the median.
- C. This is the fifth value in the ordered list, not the median.
Median
The middle value in a dataset when the values are arranged in ascending or descending order.
- Not affected by outliers.
- If n is odd, median is the (n+1)/2-th value.
- If n is even, median is the average of the two middle values.
Memory trick: Central tendency: mean is sum, median is middle, mode is most.