Basic Statistics Level 2 (Set 3).ipynb

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   "source": [
    "## Confidence Intervals"
   ]
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    "import pandas as pd\n",
    "import numpy as np\n",
    "import matplotlib.pyplot as plt\n",
    "import scipy.stats as stats\n",
    "import seaborn as sns\n",
    "import statsmodels.api as smf\n",
    "import warnings\n",
    "warnings.filterwarnings('ignore')"
   ]
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   "source": [
    "## Que no 5\n",
    "* In January 2005, a company that monitors Internet traffic (WebSideStory) reported that its sampling revealed that the Mozilla Firefox browser launched in 2004 had grabbed a 4.6% share of the market.\n",
    "* If the sample were based on 2,000 users, could Microsoft conclude that Mozilla has a less than 5% share of the market?\n",
    "\n",
    "Ans\n",
    "\n",
    "* null_hypothesis >= 5%\n",
    "* alternate hypothesis < 5%"
   ]
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       "0.20582313410777142"
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   "source": [
    "p_hat = .046\n",
    "p = .05\n",
    "n = 2000\n",
    "\n",
    "# z_score = p_hat-p/(p(1-p)/n)**0.5\n",
    "z_score = (p_hat-p)/(np.sqrt((p*(1-p))/n))\n",
    "z_score\n",
    "\n",
    "p_value = stats.norm.sf(0.821)\n",
    "p_value"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "8b69318c",
   "metadata": {},
   "source": [
    "* Find Probability assuming null hyposthesis, so as to compare with Type-1 error α = 0.05"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "d5a53337",
   "metadata": {},
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     "name": "stdout",
     "output_type": "stream",
     "text": [
      "No: Microsoft could not conclude that Mozilla has a less\n",
      "    than 5% share of the market even if the sample were \n",
      "    based on 2,000 users\n"
     ]
    }
   ],
   "source": [
    "if p_value>0.05:\n",
    "    print(\"\"\"No: Microsoft could not conclude that Mozilla has a less\n",
    "    than 5% share of the market even if the sample were \n",
    "    based on 2,000 users\"\"\")\n",
    "else:\n",
    "    print(\"Yes\")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "5cfba8f8",
   "metadata": {},
   "source": [
    "# THE END!!"
   ]
  }
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