Lower quartile range 和 upper quartile range怎樣計?
73 65 80 80 84 76 92 74 89 73 81 83 85 67 78
82 68 87 74 70 79 77 94 71 88 80 81 68 89 69
是這樣計嗎?
Q1 = the 7.75th term? (30+1)(0.25)
Q3 = the 23.25th term? (30+1)(0.75)
如果是的話, 30為什麼要加1??
請指教