The monthly rents (in dollars) paid by 7 people are given below. (Note that these are already ordered from least to greatest.)

[tex]\[
880, 910, 975, 1015, 1055, 1085, 1115
\][/tex]

Suppose that one of the people moves. Her rent changes from [tex]\(\$880\)[/tex] to [tex]\(\$1020\)[/tex]. Answer the following.

\begin{tabular}{|l|l|}
\hline
(a) What happens to the median? & It decreases by [tex]\(\$ \square\)[/tex]. \\
& It increases by [tex]\(\$ \square\)[/tex]. \\
\hline
(b) What happens to the mean? & It decreases by [tex]\(\$ \square\)[/tex]. \\
& It increases by [tex]\(\$ \square\)[/tex]. \\
& It stays the same. \\
\hline
\end{tabular}



Answer :

Let's start by examining the original and new datasets of monthly rents.

The original rents are: \[tex]$880, \$[/tex]910, \[tex]$975, \$[/tex]1015, \[tex]$1055, \$[/tex]1085, \[tex]$1115. 1. To find the original median, we locate the middle value of the ordered list. Since there are 7 values, the median is the 4th value: \[ \text{Original median} = \$[/tex]1015
\]

2. To find the original mean, we sum all the rent values and divide by the number of values (7):
[tex]\[ \text{Original mean} = \frac{880 + 910 + 975 + 1015 + 1055 + 1085 + 1115}{7} = \frac{7035}{7} = \$1005 \][/tex]

Next, one person moves and their rent changes from \[tex]$880 to \$[/tex]1020. The new rents are: \[tex]$1020, \$[/tex]910, \[tex]$975, \$[/tex]1015, \[tex]$1055, \$[/tex]1085, \[tex]$1115. 1. To find the new median, we again locate the middle value of the ordered new list. Note that the new list is still ordered: \[ \text{New median} = \$[/tex]1020.0
\]

2. To find the new mean, we sum all the new rent values and divide by the number of values (7):
[tex]\[ \text{New mean} = \frac{1020 + 910 + 975 + 1015 + 1055 + 1085 + 1115}{7} = \frac{7175}{7} = \$1025 \][/tex]

To determine the changes:

(a) Change in the median:
[tex]\[ \text{New median} - \text{Original median} = 1020 - 1015 = \$5 \][/tex]
So, the median increases by \[tex]$5. (b) Change in the mean: \[ \text{New mean} - \text{Original mean} = 1025 - 1005 = \$[/tex]20
\]
So, the mean increases by \[tex]$20. \begin{tabular}{|l|l|} \hline (a) What happens to the median? & It decreases by $[/tex]\[tex]$ \_\_\_\_\_\_. \\ It increases by $[/tex]\[tex]$ 5$[/tex]. \\
(b) What happens to the mean? & It decreases by same. [tex]$\$[/tex] \_\_\_\_\_\_. \\
& It increases by [tex]$\$[/tex] 20$. \\
& It stays the same. \\
\hline
\end{tabular}