func fourths(e) {
    var t = ((e>>1) / 2)
    [0, t, e/2, e - t, e]
}

func fivenum(nums) {
    var x = nums.sort
    var d = fourths(x.end)

    ([x[d.map{.floor}]] ~Z+ [x[d.map{.ceil}]]) »/» 2
}

var nums = [
    [15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43],
    [36, 40, 7, 39, 41, 15], [
    0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,
    0.73438555, -0.03035726,  1.46675970, -0.74621349, -0.72588772,
    0.63905160,  0.61501527, -0.98983780, -1.00447874, -0.62759469,
    0.66206163,  1.04312009, -0.10305385,  0.75775634,  0.32566578,
]]

nums.each { say fivenum(_).join(', ') }