48. An urban community was concerned about lead levels in their water supply. Lead levels were measured for one week, and the results are represented below: Sunday: 0.42, Monday: 0.48, Tuesday: 0.66, Wednesday: 0.73, Thursday: 1.10, Friday: 1.10, Saturday: 5.40. What is the median level?
Answer: A
The median lead level in the water supply is 0.73.
To find the median level of lead, the values must be arranged in ascending order: 0.42, 0.48, 0.66, 0.73, 1.10, 1.10, 5.40. The median is the middle value in this ordered list, which is 0.73.
A) 0.73
This option is correct as it represents the median of the sorted lead levels. With seven data points, the median is the fourth value in the ordered list, which is indeed 0.73.
B) 1.1
This option is incorrect because while 1.10 is one of the lead levels measured, it is not the median. In the ordered list, it is the fifth and sixth values, thus not the middle value.
C) 1.41
This option is incorrect as 1.41 is not one of the measured lead levels. Therefore, it cannot be the median, which must be one of the actual measured values.
D) 0.42
This option is incorrect because 0.42 is the first value in the ordered list and does not represent the median. The median, being the middle value, is actually 0.73.
Conclusion
The correct answer is 0.73, as it accurately reflects the median of the lead levels measured in the water supply. All other options either misrepresent the median or are not valid values from the data set. Understanding how to find the median is essential for interpreting data sets correctly.