Answer:
The mode of this list of numbers would still be [tex]7[/tex] (the mode did not change) after "[tex]5[/tex]" was added to the list.
Step-by-step explanation:
The mode of a list of elements is the member that appears the most frequently.
The original list of numbers in this question [tex][5,\, 7,\, 7,\, 7,\, 1,\, 2,\, 9,\, 8][/tex] included the following members:
[tex]\begin{array}{c|c} \text{Member} & \text{Number of appearances} \\ \hline\hline 1 & 1 \\\hline 2 & 1 \\\hline 5 & 1\\\hline 7 & 3 \\\hline 8 & 1 \\\hline 9 & 1 \\\end{array}[/tex]
[tex]\begin{array}{c|c} \text{Member} & \text{Number of appearances} \\ \cline{1-2}\\[-1em]\cline{1-2} 1 & 1 \\\cline{1-2} 2 & 1 \\\cline{1-2} 5 & 1\\\cline{1-2} 7 & 3 \\\cline{1-2} 8 & 1 \\\cline{1-2} 9 & 1 \\\end{array}[/tex].
The member "[tex]7[/tex]" appeared more often than any other member of this list. Thus, the mode of the original list was "[tex]7\![/tex]".
Adding "[tex]5[/tex]" to the original list would give the list [tex][5,\, 7,\, 7,\, 7,\, 1,\, 2,\, 9,\, 8,\, 5][/tex]. Members of this list are:
[tex]\begin{array}{c|c} \text{Member} & \text{Number of appearances} \\ \hline\hline 1 & 1 \\\hline 2 & 1 \\\hline 5 & 2\\\hline 7 & 3 \\\hline 8 & 1 \\\hline 9 & 1 \\\end{array}[/tex]
[tex]\begin{array}{c|c} \text{Member} & \text{Number of appearances} \\ \cline{1-2}\\[-1em]\cline{1-2} 1 & 1 \\\cline{1-2} 2 & 1 \\\cline{1-2} 5 & 2\\\cline{1-2} 7 & 3 \\\cline{1-2} 8 & 1 \\\cline{1-2} 9 & 1 \\\end{array}[/tex].
The member "[tex]7[/tex]" still appeared more often than any other member of this list. Thus, the mode of the new list would also be "[tex]7\![/tex]".
