At A Small Construction Site, The Number Of Workers On-Site During Five Consecutive Days Was As Follows: Big Data Epidemiology Coursework, OU, Ireland
Epidemiology and data collection
Part 1
At a small construction site, the number of workers on-site during five consecutive days was as follows:
| Day of week | Number of Workers |
| Monday
Tuesday Wednesday Thursday Friday |
1
2 3 3 1 |
Complete the following table:
| No. of workers
(X) |
(No of days) Frequency
(F) |
(FX) |
(FX2) |
| 1
2 3 |
|
||
| Total |
Fill in the blanks below to calculate the mean, median and standard deviation of the number of workers on-site per day:
Here and Mean number of workers per day. In order of magnitude, the data is 1, 1, 2, 3, 3.
Hence the median = workers per day.
The standard deviation of the number of workers per day is given by:
Complete the following table:
Number of workers per day
| Median | Mean | Standard Deviation |
|
|
Part 2
The ages of 10 workers on a particular building site are:
40, 38, 29, 49, 30, 27, 50, 49, 49, 39
Fill in the blanks in the following:
Here the number of workers is = and the sum of all of their ages is = years.
Hence the mean age of the workers in Department A is:
Mean = years
The standard deviation of the ages of the workers in Department A is 9.1 years (There is no need to calculate this)
There are 20 workers in Department B. The age distribution in the two departments is summarised below:
| Department | Mean | Standard Deviation |
| A
B |
36 |
9.1
10.3 |
Complete the following statements:
- The average age is higher in which department?
- The age distribution is more variable in which department?
Part 3 (6 Marks)
Two samples of employees from Companies A and B are examined. The sample size for Company A was 60 and the sample size for Company B was 40.
The number of lost workdays (LWD) in the last two years is recorded for each employee. A selection of descriptive statistics is presented below. Answer each question using the statistics.
| N | Mean | Median | Standard Deviation | |
| Company A | 60 | 6.2 | 6.0 | 1.5 |
| Company B | 40 | 6.4 | 6.3 | 4.5 |
What shape would the distribution of LWD for Companies A and B follow if histograms could be plotted? Explain your answer. (note – do not attempt to plot histograms as it is not possible.)
Answer
Choose either the mean or the median and compare the average number of LWD for the companies. Justify your choice of statistic.
Answer
Compare the variability between both companies.
