Begin statistics creation

CHDataManagement/Extensions/Double+Rounded.swift

@@ -1,7 +1,14 @@
+import Foundation
+import _math
 
 extension Double {
 
     func rounded(to interval: Double) -> Double {
         (self / interval).rounded() * interval
     }
+
+    func rounded(decimals: Int) -> Double {
+        let factor = _math.pow(10.0, Double(decimals))
+        return (self * factor).rounded() / factor
+    }
 }