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 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("", (0,5*dayheight), N);
label("", (2*unitwidth,5*dayheight), N);
label("", (4*unitwidth,5*dayheight), N);
label("", (6*unitwidth,5*dayheight), N);
label("", (8*unitwidth,5*dayheight), N);
label("", (10*unitwidth,5*dayheight), N);
label("", (12*unitwidth,5*dayheight), N);
label("", (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]