Answer:
(a)Mean: It increases by $23.
(b)Median: It stays the same.
Explanation:
The weekly salaries are given below:
[tex]538,727,807,828,900,920,929[/tex]Part A
First, we find the mean of the initial salaries:
[tex]Mean=\frac{538+727+807+828+900+920+929}{7}=\frac{5649}{7}=807[/tex]If the $538 salary changes to $699, then:
[tex]Mean=\frac{699+727+807+828+900+920+929}{7}=\frac{5810}{7}=830[/tex]The difference = 830-807=23.
Therefore, if the $538 salary changes to $699, the mean increases by $23.
Part B
The median is the item in the middle of the data.
The initial weekly salaries are:
[tex]\begin{gathered} 538,727,807,828,900,920,929 \\ \implies Median=828 \end{gathered}[/tex]If the $538 salary changes to $699, the new weekly salaries are:
[tex]\begin{gathered} 699,727,807,828,900,920,929 \\ \implies Median=828 \end{gathered}[/tex]The median stays the same.