MathDB
Soccer Practice

Source: 2019 AMC 8 #10

December 26, 2019
AMC 8

Problem Statement

The diagram shows the number of students at soccer practice each weekday during last week. After computing the mean and median values, Coach discovers that there were actually 2121 participants on Wednesday. Which of the following statements describes the change in the mean and median after the correction is made?
[asy] unitsize(1 cm);
real unitwidth, dayheight, barheight; int i;
unitwidth = 0.5; dayheight = 1; barheight = 0.3;
draw((unitwidth,0)--(unitwidth,5*dayheight),gray(0.7)); draw((2*unitwidth,0)--(2*unitwidth,5*dayheight),gray(0.7)); draw((3*unitwidth,0)--(3*unitwidth,5*dayheight),gray(0.7)); draw((4*unitwidth,0)--(4*unitwidth,5*dayheight),gray(0.7)); draw((5*unitwidth,0)--(5*unitwidth,5*dayheight),gray(0.7)); draw((6*unitwidth,0)--(6*unitwidth,5*dayheight),gray(0.7)); draw((7*unitwidth,0)--(7*unitwidth,5*dayheight),gray(0.7));
fill((0,1/2*dayheight - 1/2*barheight)--(8*unitwidth,1/2*dayheight - 1/2*barheight)--(8*unitwidth,1/2*dayheight + 1/2*barheight)--(0,1/2*dayheight + 1/2*barheight)--cycle,gray(0.5));
fill((0,5/2*dayheight - 1/2*barheight)--(8*unitwidth,5/2*dayheight - 1/2*barheight)--(8*unitwidth,5/2*dayheight + 1/2*barheight)--(0,5/2*dayheight + 1/2*barheight)--cycle,gray(0.5));
draw((8*unitwidth,0)--(8*unitwidth,5*dayheight),gray(0.7)); draw((9*unitwidth,0)--(9*unitwidth,5*dayheight),gray(0.7));
fill((0,9/2*dayheight - 1/2*barheight)--(10*unitwidth,9/2*dayheight - 1/2*barheight)--(10*unitwidth,9/2*dayheight + 1/2*barheight)--(0,9/2*dayheight + 1/2*barheight)--cycle,gray(0.5));
draw((10*unitwidth,0)--(10*unitwidth,5*dayheight),gray(0.7));
fill((0,3/2*dayheight - 1/2*barheight)--(11*unitwidth,3/2*dayheight - 1/2*barheight)--(11*unitwidth,3/2*dayheight + 1/2*barheight)--(0,3/2*dayheight + 1/2*barheight)--cycle,gray(0.5));
draw((11*unitwidth,0)--(11*unitwidth,5*dayheight),gray(0.7)); draw((12*unitwidth,0)--(12*unitwidth,5*dayheight),gray(0.7));
fill((0,7/2*dayheight - 1/2*barheight)--(13*unitwidth,7/2*dayheight - 1/2*barheight)--(13*unitwidth,7/2*dayheight + 1/2*barheight)--(0,7/2*dayheight + 1/2*barheight)--cycle,gray(0.5));
draw((0*unitwidth,0)--(0*unitwidth,5*dayheight),gray(0.7)); draw((13*unitwidth,0)--(13*unitwidth,5*dayheight),gray(0.7)); draw((14*unitwidth,0)--(14*unitwidth,5*dayheight),gray(0.7));
label("00", (0,5*dayheight), N); label("44", (2*unitwidth,5*dayheight), N); label("88", (4*unitwidth,5*dayheight), N); label("1212", (6*unitwidth,5*dayheight), N); label("1616", (8*unitwidth,5*dayheight), N); label("2020", (10*unitwidth,5*dayheight), N); label("2424", (12*unitwidth,5*dayheight), N); label("2828", (14*unitwidth,5*dayheight), N); label("Number of students at soccer practice", (7*unitwidth,6*dayheight)); label("Monday", (-0.5*unitwidth,9/2*dayheight), W); label("Tuesday", (-0.5*unitwidth,7/2*dayheight), W); label("Wednesday", (-0.5*unitwidth,5/2*dayheight), W); label("Thursday", (-0.5*unitwidth,3/2*dayheight), W); label("Friday", (-0.5*unitwidth,1/2*dayheight), W); [/asy]
<spanclass=latexbold>(A)</span>The mean increases by 1 and the median does not change.<span class='latex-bold'>(A) </span> \text{The mean increases by 1 and the median does not change.}
<spanclass=latexbold>(B)</span>The mean increases by 1 and the median increases by 1.<span class='latex-bold'>(B) </span> \text{The mean increases by 1 and the median increases by 1.}
<spanclass=latexbold>(C)</span>The mean increases by 1 and the median increases by 5.<span class='latex-bold'>(C) </span> \text{The mean increases by 1 and the median increases by 5.}
<spanclass=latexbold>(D)</span>The mean increases by 5 and the median increases by 1.<span class='latex-bold'>(D) </span> \text{The mean increases by 5 and the median increases by 1.}
<spanclass=latexbold>(E)</span>The mean increases by 5 and the median increases by 5.<span class='latex-bold'>(E) </span> \text{The mean increases by 5 and the median increases by 5.}