Waiting Time Investigation - Casio FX-82AU PLUS Using Manual

On average, how long do customers wait in your school canteen queue before they have
completed their purchases? In this activity you will be investigating this question and evaluating
the results.
Equipment required
· A watch that measures time in minutes and seconds
· Pen and paper for recording results
· A Casio fx­82AU PLUS calculator
What you have to do
· In groups of 3 assign each person one of the roles of timer, recorder or customer selector.
· Arrange for different groups to measure customer­waiting times at the beginning, middle
and end of buying times.
· To make sure your results are valid it is important to choose a random sample of
customers to time. The 'customer selector' will use the calculator's random number
generator to choose customers. Set the calculator to Line10 and fix the display to show 2
decimal places. When you press SHIFT . p the calculator will show a decimal
number. If the random number is less than 0.50 select the next customer that joins the line
to time. Each time you press p another random number will be displayed.
· The 'timer' measures the time from when the selected customer joins the queue until they
move away from the counter.
· Record the time for at least 10 randomly selected customers.
Calculating the mean (average) time
· Set the calculator to statistics by pressing MODE then 2 (for stats) then 1 (for 1­
VAR).
· Use the x button to enter the waiting times in minutes and seconds. e.g. enter 2 minutes
and 35 seconds by pressing 2 x 35 x and the calculator will display the
amount automatically as 2.5833 minutes. After you have entered all the times press C.
Then press SHIFT 1 (stats) 4 (Var). The screen options show that pressing 2 will
give the mean. Press 2 then p to find the mean of the times. The calculator will show
the time as a decimal. Press SHIFT x to show the time in minutes and seconds.
Evaluating your results
· Compare the results from different groups. Are they the same? If they are different
suggest a reason for the difference.
· Use the information to determine whether customers have to wait too long. If the times
are too long, can you suggest a way to shorten the time?
Who is interested in your results?
Write a report of your investigation and your findings. Give the report to someone who can
implement any suggestions you can make.
© Sue Thomson and Shriro Australia PTY Limited. This page may be photocopied for classroom use.
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