Because of these infl uencing factors, it is important to understand how to evaluate statistical information so that you can be a statistically aware citizen.
In an attempt to prevent companies from misleading customers, there are laws and standards that companies have to adhere to when advertising their products. You may have noticed that in certain advertisements, they will tell you how many people were surveyed.
Worked example
Linda attends a school of 400 students. She conducted a survey using a random sample of the junior students in her school. She drew the graphs below to represent the data she collected. What conclusions could Linda make from the data shown?
Gender
25 30 35 40
Boys 92
Girls 94
15 20
10 5
Lunchtime activities
Boys Girls
Mean
Median Mode Range
Activities Solution Age
14·214 13·5 14 3
Practice questions 26.4
1. Daniel owns a gym. He wants to investigate if lifting heavier weights aff ects how many reps a person can complete. The table below shows the results of an observational study he conducted.
Weight lifted (kg) Number of reps 100 115 130 145
32 24 16 8
(i) Can you identify any pattern/ trend from this table?
(ii) What conclusion could Daniel draw from this data?
(iii) Can you think of any possible limitations to this conclusion?