Answer :
To find the median of the data set 21, 42, 63, 84, 105, 126, 147, follow these steps:
1. Understand the Concept of Median: The median is the middle value of a data set when the numbers are arranged in order from least to greatest. If there's an odd number of observations, the median is the middle number. If there's an even number of observations, the median is the average of the two middle numbers.
2. Ensure the Data Set is Sorted: Before you find the median, make sure the data set is in numerical order. In this case, the data set is already sorted: 21, 42, 63, 84, 105, 126, 147.
3. Determine the Number of Observations: Count the number of values in the data set. Here, there are 7 numbers.
4. Locate the Middle Value: Since there are 7 numbers, which is an odd number, the median will be the fourth number in the sorted list (as 7 divided by 2 is 3.5, so you'll look at the position right after the whole number 3, which is 4).
5. Identify the Median: The fourth number in the sorted data set is 84.
Therefore, the median of the data set is 84. So, the correct answer is:
C. 84
1. Understand the Concept of Median: The median is the middle value of a data set when the numbers are arranged in order from least to greatest. If there's an odd number of observations, the median is the middle number. If there's an even number of observations, the median is the average of the two middle numbers.
2. Ensure the Data Set is Sorted: Before you find the median, make sure the data set is in numerical order. In this case, the data set is already sorted: 21, 42, 63, 84, 105, 126, 147.
3. Determine the Number of Observations: Count the number of values in the data set. Here, there are 7 numbers.
4. Locate the Middle Value: Since there are 7 numbers, which is an odd number, the median will be the fourth number in the sorted list (as 7 divided by 2 is 3.5, so you'll look at the position right after the whole number 3, which is 4).
5. Identify the Median: The fourth number in the sorted data set is 84.
Therefore, the median of the data set is 84. So, the correct answer is:
C. 84
