Questions: Find the median for the group of data items.
99, 99, 91, 35, 73, 99
A. 95
B. 35
C. 99
D. 91
Transcript text: Find the median for the group of data items.
\[
99,99,91,35,73,99
\]
A. 95
B. 35
C. 99
D. 91
Solution
Solution Steps
Step 1: Sort the Data
To find the median, we first sort the data set. The given data items are:
\[
99, 99, 91, 35, 73, 99
\]
After sorting, we have:
\[
\text{Sorted data} = [35, 73, 91, 99, 99, 99]
\]
Step 2: Calculate the Rank
The formula for the rank \( R \) to find the median (quantile \( Q \)) is given by:
\[
R = Q \times (N + 1)
\]
where \( N \) is the number of data points. Here, \( N = 6 \) and \( Q = 0.5 \) (for the median). Thus, we calculate:
\[
R = 0.5 \times (6 + 1) = 0.5 \times 7 = 3.5
\]
Step 3: Determine the Median
Since \( R = 3.5 \) is not an integer, we take the average of the values at ranks 3 and 4 in the sorted data. The values at these ranks are:
\( X_{\text{lower}} = 91 \) (rank 3)
\( X_{\text{upper}} = 99 \) (rank 4)
Using the averaging formula:
\[
Q = \frac{X_{\text{lower}} + X_{\text{upper}}}{2} = \frac{91 + 99}{2} = \frac{190}{2} = 95.0
\]