A factory produces two types of shirt: A and B. To calculate how many of each to produce, the factory gathered data on the sales of their shirts at each of five shopping centres. The table shows the sales of a sample of 100 shirts for each shopping centre. Which type of shirt is more popular?
We can see from the table that, in shopping centre one and shopping centre two, then type A was more popular. However, in shopping centre three, four, and five, type B was the more popular shirt. In order to decide which is the more popular shirt overall, we need to look at the total numbers.
The total number of sales of shirt type A can be calculated by adding 87, 51, 26, 23, and 24. This gives us 211, which means that, out of the whole sample of 500 shirts, 211 of type A were sold.
In a similar way, we can work out the total of type B by adding 13, 49, 74, 77, and 76. Adding these numbers gives us a total of 289. This means that 289 out of the sample of 500 shirts were sold of type B.
As 289 is greater than 211, we can say that type B is the more popular shirt. In order to increase the reliability of this data, we could increase the sample size over a longer period of time within each shopping centre.