Answer:
- The mean will decrease, and the median will stay the same.
Explanation:
Using asterisks, instead of dots, this is the described plot:
Number of minutes, to the nearest five minutes, that Sarah spent getting ready for school each morning:
* *
* * * * *
* * * * * *
5 10 15 20 25 30 35 40 45 50 55 60
If the new point, 15 minutes, is added to the graph, the new graph is:
* *
* * * * *
* * * * * * *
5 10 15 20 25 30 35 40 45 50 55 60
Review what happens with the mean and the median of both sets of data.
The mean will decrease:
It is correct that the mean will decrease because you must include a number with lower value in the formula which pulls the mean downward.
The formula is:
- Mean = Sum of the values / number of values.
- By adding a low value (lower than the previous mean) the calculation of the new mean will result in a lower value
The median will stay the same:
For the first graph there are 13 dots; thus, the median is the value for the seventh dot, which is 45.
For the second graph there are 14 dots; thus, the median is the average of the seventh and the eighth values. Both the seventh and the eighth values are 45, so the average is also 45.
Hence, the mean will decrease and the median will stay the same.
