Final answer:
The third quartile, Q3, for company A is the median of the upper half of the dataset. It is equivalent to the middle value among the upper values if the number of data points is odd, or the average of the two middle values if even. In the provided example, Q3 is specifically given as 9.
Step-by-step explanation:
The value of the third quartile, Q3, for company A is found by identifying the median of the upper half of the data set, excluding the overall median. According to the provided information, there are seven data values in the upper half. Therefore, the third quartile is the middle value of these seven values. If the middle value is given as 60 for another context or set of data, you should look for the middle value in your specific data set for company A to determine Q3.
However, in the example provided, it states that the median of the upper half, or Q3, will be the middle value of the upper half, which is 9. Sometimes we may refer to the third quartile as the 75th percentile, which can be found by ranking the data and finding the value at the 75th percentile. In a different context, you may find Q3 by tallying the data and identifying the point at which 75% of the data lies below.
Lastly, the Interquartile Range (IQR), which measures the spread of the middle 50% of the data, is calculated as Q3 minus the first quartile, Q1. This can help us understand the variability around the median.