Bar Graph

Find the mean and standard deviation of a list of numbers.

Complete Code

POD for Macro Files

PG problem file

Explanation

DOCUMENT();

loadMacros(
    "PGstandard.pl", "PGML.pl",
    'PGtikz.pl',     'contextPercent.pl',
    "PGcourse.pl"
);

Preamble

The PGtikz.pl macro provides the graphing methods we will use in this problem and contextPercent.pl will be to provide the Percent context.


Context('Percent');

@grades = map { random(1, 5) } (0 .. 3);

$graph = createTikZImage();
$graph->tikzLibraries('arrows.meta');
$graph->BEGIN_TIKZ
\tikzset{>={Stealth[scale = 1.5]}}
\filldraw[
    draw = LightBlue,
    fill = white,
    rounded corners = 10pt,
    thick,
    use as bounding box
] (-1, -1) rectangle (11, 7);
\draw[->, thick] (-1, 0) -- (10, 0);

\foreach \x/\label in {2/A,4/B,6/C,8/D}
    \draw(\x,0.25)--(\x,-0.25) node [below] {\label};
\draw[-, thick] (0, -1) -- (0, 6);
\foreach \y in {1, ..., 5}
    \draw (5pt, \y) -- (-5pt, \y) node[left] {\(\y\)};

\filldraw[fill=LightBlue, draw=black] (1.2,0) rectangle (2.8,$grades[0]);
\filldraw[fill=LightSalmon, draw=black]  (3.2,0) rectangle (4.8,$grades[1]);
\filldraw[fill=LightYellow, draw=black]  (5.2,0) rectangle (6.8,$grades[2]);
\filldraw[fill=LightGreen, draw=black]  (7.2,0) rectangle (8.8,$grades[3]);

END_TIKZ

$alt_text =
    "A bar graph with vertical bars.  The height of the bar labelled A "
    . "is $grades[0]. The height of the bar labelled B is $grades[1].  "
    . " The height of the bar labelled C is $grades[2] and finally the "
    . "bar labelled D is $grades[3].";

# This code adds up all the numbers in the @grades array.
$num_students = 0;
$num_students += $_ for @grades;

$perA = Real($grades[0] / $num_students);

Setup

The ‘Percent’ context allow students to enter percents. The graph is created dynamically. The axes are created with the given labels. Extending the number of bars or the height of the bars should be similar to this code. The heights of the bars are the grades which are generated randomly with the perl map function. If you want a non uniform distribution, you can create a different range of random numbers for each grade level.

Make sure that an alternate text is added to all graphs for accessibility. Be detailed.

BEGIN_PGML
The following is a distribution of grades on a Statistics quiz.
>>[! [$alt_text] !]{$graph}{400}<<

What percentage of students earned an A? [_]{$perA}
END_PGML

Statement

In this case, we plot the bar graph and ask a question. Since the context is ‘Percent’, the students can answer the question with either a fraction, decimal or percent. If only percent answers is desired, see the flags for the Percent context in the macro.

BEGIN_PGML_SOLUTION
The total number of students that took the quiz is [$total] so the percentage is
the number of A students or [`[$grades[0]]/[$num_students] = [$perA] `]
END_PGML_SOLUTION

ENDDOCUMENT();

Solution

A solution should be provided here.