TMP36 Temperature Sensor questions.

Hey guys, i am brand new to all this but i bought a Inventors kit from robotshop.ca and i was following the guide for putting together temperature recording layout when i went to watch the temperature the numbers are this:
303.03
258.11
224.41
194.63
169.24
148.73
132.62
119.92
109.67
100.88
94.04
89.65
87.21
85.74
85.25
85.25
86.72
88.18
89.65
90.63

now i know for a fact that my temperature inside is currently sitting a 74.4f but this sensor doesn't dip below 80..... and it varies so much i have the feeling its broken or what i am looking at is not infact the temperature.... i just wanted to get some feedback as this is a critical area for me to learn (i plan on building a temperature sensor that controls a fan).

Heres the code it is running, again i am a complete noobie so i have no idea what to look for yet.

/* ---------------------------------------------------------

  • | Arduino Experimentation Kit Example Code |
  • | CIRC-10 .: Temperature :. (TMP36 Temperature Sensor) |

  • A simple program to output the current temperature to the IDE's debug window
  • For more details on this circuit: http://tinyurl.com/c89tvd
    */

//TMP36 Pin Variables
int temperaturePin = 0; //the analog pin the TMP36's Vout (sense) pin is connected to
//the resolution is 10 mV / degree centigrade
//(500 mV offset) to make negative temperatures an option

/*

  • setup() - this function runs once when you turn your Arduino on
  • We initialize the serial connection with the computer
    */
    void setup()
    {
    Serial.begin(9600); //Start the serial connection with the copmuter
    //to view the result open the serial monitor
    //last button beneath the file bar (looks like a box with an antenae)
    }

void loop() // run over and over again
{
float temperature = getVoltage(temperaturePin); //getting the voltage reading from the temperature sensor
temperature = (temperature - .5) * 100; //converting from 10 mv per degree wit 500 mV offset
//to degrees ((volatge - 500mV) times 100)
Serial.println(temperature); //printing the result
delay(1000); //waiting a second
}

/*

  • getVoltage() - returns the voltage on the analog input defined by
  • pin
    */
    float getVoltage(int pin){
    return (analogRead(pin) * .004882814); //converting from a 0 to 1023 digital range
    // to 0 to 5 volts (each 1 reading equals ~ 5 millivolts
    }

you need to check if your source voltage is indeed 5.0V because the whole code is based upon that.

please use code tags - it is the # button above the smileys