Discuss the below:
Percentile: We show two methods for calculating a percentile:
| The weights (in pounds) of 18 preschool children are |
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| 47 |
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Q: Find 25th and 60th percentiles for these weights
Method A: To find a pth percentile of a sample of rz observations:
1. Order the n observations from smallest to largest.
2. Determine the value of n X 100. This value is used to find the position of the pth percentile in the ordered list.
If n X - 100 is not an integer, round it up to the next integer. The observation in this position is the pth percentile. c If n X - 100 is an integer, calculate the mean of the observations in this position and the next (higher) position. This mean is the pth percentile.
Method B:
To find a pth percentile of a sample of rz observations:
1. Order the n observations from smallest to largest.
2. Determine the value of (n+1) X 100-. This value is used to find the position of the pth percentile in the ordered list.
• If (n+1) X - 100 is an integer, the observation in this position is a pth percentile.
• If (n+1) X - 100 is not an integer but equal to k plus some proper fraction d, the pth percentile is a value lying d of the distance between the observations in the kth and (k+1)th positions.