Data commit

Task/Cumulative-standard-deviation/Groovy/cumulative-standard-deviation.groovy

@@ -0,0 +1,13 @@
+List samples = []
+
+def stdDev = { def sample ->
+    samples << sample
+    def sum = samples.sum()
+    def sumSq = samples.sum { it * it }
+    def count = samples.size()
+    (sumSq/count - (sum/count)**2)**0.5
+}
+
+[2,4,4,4,5,5,7,9].each {
+    println "${stdDev(it)}"
+}