Mitch decides to employ an extra person for a two-hour time period. Which time period would you suggest?
How to approach this question
1. The goal of hiring an extra person is to reduce waiting times when they are highest.
2. Look at all the data available: the initial scatter plot and the information from the previous question.
3. The initial plot shows waiting times increasing throughout the morning, peaking towards the right side of the graph.
4. The information from 8(b)(ii) states that between 12.30pm and 1.30pm, waiting times were consistently high (between 4 and 5 minutes).
5. This period (around 12.30pm - 1.30pm) is clearly the busiest, with the longest waiting times.
6. Therefore, the extra person should be employed during this peak period to be most effective.
7. Suggest a two-hour period that covers this peak, for example, 12:30pm to 2:30pm, or 12:00pm to 2:00pm.
Full Answer
From 12:30pm to 2:30pm (or similar period covering the lunchtime peak).
The purpose of employing an extra person is to reduce service time during the busiest periods. By analysing the data, we can identify when this is. The initial scatter plot shows a positive correlation, meaning waiting times increase as the day progresses towards midday. The additional information confirms this, stating that between 12.30pm and 1.30pm, waiting times were at their peak, between 4 and 5 minutes. This is the clear lunchtime rush. Therefore, the most logical time to employ an extra person would be to cover this period. A two-hour slot like 12.30pm to 2.30pm would cover the peak and the period immediately after, helping to reduce the backlog.
Common mistakes
✗ Suggesting a time in the morning when waiting times are low.
✗ Suggesting a time late in the afternoon. Although we don't have data, the trend suggests it would be quieter after the lunchtime peak.
Expert