Answer:
- <u><em>The mean will decrease, and the median will stay the same.</em></u>
Explanation:
Using asterisks, instead of dots, this is the described plot:
<em>Number of minutes, to the nearest five minutes, that Sarah spent getting ready for school each morning:</em>
* *
* * * * *
* * * * * *
5 10 15 20 25 30 35 40 45 50 55 60
If the <em>new point</em>, <em>15 minutes</em>, is <em>added to the graph</em>, 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.
<em>The mean will decrease:</em>
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
<em>The median will stay the same:</em>
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,<em> the mean will decrease and the median will stay the same.</em>