CEMC Banner

Problem of the Week
Problem B and Solution
Trucks, Bikes, and Cars

Problem

Mohammed wants to graph a record of the traffic that goes by his house between \(4\):\(30\) p.m. and \(4\):\(40\) p.m. He creates a data collection sheet and collects the following data while standing on the sidewalk beside his home during that period.

Time Vehicle
\(4\):\(30\).\(12\) Car
\(4\):\(30\).\(43\) Car
\(4\):\(31\).\(24\) Truck
\(4\):\(31\).\(58\) Bicycle
\(4\):\(32\).\(34\) Car
\(4\):\(33\).\(08\) Car
Time Vehicle
\(4\):\(33\).\(37\) Truck
\(4\):\(34\).\(21\) Car
\(4\):\(34\).\(52\) Car
\(4\):\(35\).\(23\) Car
\(4\):\(36\).\(14\) Bicycle
\(4\):\(36\).\(45\) Truck
Time Vehicle
\(4\):\(37\).\(29\) Car
\(4\):\(38\).\(36\) Bicycle
\(4\):\(39\).\(16\) Truck
\(4\):\(39\).\(48\) Car
\(4\):\(40\).\(10\) Car
\(4\):\(40\).\(38\) Car

  1. Is the data Mohammed collected primary or secondary data?

  2. What type of graph or plot would be appropriate to display this data?

  3. Create this graph or plot using proper titles and labels.

Solution

  1. The data Mohammed collected is primary since he collected it. (If he gave the data to city planners to use, then it would be secondary data to them, as they did not collect it themselves.)

  2. The appropriate type of graph or plot depends on its purpose. Some ideas include a stem-and-leaf plot for minutes and seconds which displays when each vehicle passed, or a bar graph or circle graph to contrast the numbers or ratios of cars, trucks, and bicycles.

  3. Examples of a stem-and-leaf plot, a bar graph, and a circle graph are shown below.

    Traffic In Front of My House
    Stem Leaf
    \(4\):\(30\) \(~12\) \(~43~\)
    \(4\):\(31\) \(~24\) \(~58~\)
    \(4\):\(32\) \(~34~\)
    \(4\):\(33\) \(~08\) \(~37~\)
    \(4\):\(34\) \(~21\) \(~42~\)
    \(4\):\(35\) \(~23~\)
    \(4\):\(36\) \(~14\) \(~45~\)
    \(4\):\(37\) \(~29~\)
    \(4\):\(38\) \(~36~\)
    \(4\):\(39\) \(~16\) \(~48~\)
    \(4\):\(40\) \(~10\) \(~38~\)

    Key: \(4\):\(40\) \(\vert\) \(10\) \(=\) \(4\):\(40\).\(10\) p.m.

    A bar graph of Traffic in Front of My House. The vertical axis ranges from 0 to 12 counting by 2s. The bar for Car has a height between 10 and 12. The bar for Truck has a height of 4. The bar for Bicycle has a height between 2 and 4.

    A circle graph of Traffic in Front of My House. The section for Car is eleven eighteenths or 61.1 percent of the circle. The section for Truck is four eighteenths or 22.2 percent of the circle. The section for Bicycle is three eighteenths or 16.7 percent of the circle. These three sections make up the whole circle.