The original data is:
405, 1108, 84, 315, 495, 609, 362, 428, 224, 338, 700, 790, 814, 767, 633
To find the required percentiles, we need to sort the dataset from lowest to highest.
84, 224, 315, 338, 362, 405, 428, 495, 609, 633, 700, 767, 790, 814, 1108
The total number of data is 15.
a) The 25th percentile is the element located at the position:
25/100 * 15 = 3.75
Rounding down, the position is 3, so the 25th perc