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     "text": [
      "Sample Data:  [4, 2, 5, 8, 6]\n",
      "Standard Deviation :  2.23606797749979\n"
     ]
    }
   ],
   "source": [
    "# Write a Python program to calculate the standard deviation of the following data.\n",
    "# Input\n",
    "# Sample Data:  [4, 2, 5, 8, 6]                                                                                 \n",
    "# Output\n",
    "# Standard Deviation :  2.23606797749979\n",
    "\n",
    "import math\n",
    "import sys\n",
    "\n",
    "def sd_calc(data):\n",
    "    n = len(data)\n",
    "\n",
    "    if n <= 1:\n",
    "        return 0.0\n",
    "\n",
    "    mean, sd = avg_calc(data), 0.0\n",
    "\n",
    "    # calculate stan. dev.\n",
    "    for el in data:\n",
    "        sd += (float(el) - mean)**2\n",
    "    sd = math.sqrt(sd / float(n-1))\n",
    "\n",
    "    return sd\n",
    "\n",
    "\n",
    "def avg_calc(ls):\n",
    "    n, mean = len(ls), 0.0\n",
    "\n",
    "    if n <= 1:\n",
    "        return ls[0]\n",
    "\n",
    "    # calculate average\n",
    "    for el in ls:\n",
    "        mean = mean + float(el)\n",
    "    mean = mean / float(n)\n",
    "\n",
    "    return mean\n",
    "\n",
    "data = [4, 2, 5, 8, 6]\n",
    "print(\"Sample Data: \",data)\n",
    "print(\"Standard Deviation : \",sd_calc(data))"
   ]
  }
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