Aurelia and Darius each surveyed 12 different teachers in their middle school. The teachers were asked how many years they have been teaching. The table shows the mean, median, and range for the data from each survey.
Aurelia's
Survey Results Darius'
Survey Results
Mean 7.8 years 9.4 years
Median 13.5 years 11.5 years
Range 21.0 years 23.0 years
Mode 7 years 3 years
Based on the data, which conclusion is NOT valid?
Responses
A The range for the number of years that teachers at this middle school have been teaching is greater than 20 years.The range for the number of years that teachers at this middle school have been teaching is greater than 20 years.
B The mean number of years that teachers at this middle school have been teaching is less than 10 years.The mean number of years that teachers at this middle school have been teaching is less than 10 years.
C The median number of years that teachers at this middle school have been teaching is 12.5 years.The median number of years that teachers at this middle school have been teaching is 12.5 years.
D The mode number of years that teachers at this middle school have been teaching cannot be determined from the data in the table.
C. The median number of years that teachers at this middle school have been teaching is 12.5 years.
This conclusion is not valid because the data provided in the table shows that the median for Aurelia's survey results is 13.5 years and for Darius' survey results is 11.5 years. Therefore, the median is not 12.5 years for either survey.