### Averages And Probability

Due to the speed inwhich we were taught this lesson... and the pie distracting me ;) there may be some things I might have missed, so here it goes...

Today we learned some tricks for the TI-83's and it had to do with averages and probability (thus the name) so I'll try to recreate them as best as I can.

First we were given a list of 6 weights of potatoe sacks from 2 different farmers (6 each)

To enter the numbers press:

[stat]->[enter]-> enter the data in the respective lists -> [2nd]->[mode]

When the numbers have been entered in the lists and all is complete we now can change the information into 1-Variable Statistics by pressing:

[stat]->[>](calc)->[1](1-var Stats)->[2nd]->[1](L1)->[enter]

The screen now displays the following info:

X=50 (average of list 1)

ƩX=300 (sum of all numbers on list)

ƩX

SX=2.3664... (sample deviation)

őX=2.16024... (standard deviation)

n=6 (number of numbers on list)

minX=47 (minimum)

Q1=48 (inbetween minimum and middle)

med=50 (middle)

Q3=52 (inbetween middlde and maximum)

maxX=53 (maximum)

Pressing the same keys as before but replacing 2 for 1 like so:

[stat]->[>](calc)->[1](1-var Stats)->[2nd]->[2](L2)->[enter]

will give the results above but for list 2

X=50

ƩX=300

ƩX

SX=11.83215957

őX=10.8012345

n=6

minX=35

Q1=40

med=50

Q3=60

maxX=65

Another thing we learned was how to put info into a probability graph

we used pennies as an example and thier weights.

With this data now entered into the lists we press:

[stat]->[>]->[1]->[2nd]->[1]->[,]->[2nd]->[2]

This mulitplies the numbers together to create a result we wanted (to tell the probability of a penny of a certian weight happening)

X=3.087

ƩX=926.1

ƩX

SX=0.1223

őX=0.12219

n=300

minX=2.7

Q1=3

med=3.1

Q3=3.2

maxX=3.4

Hitting [stat]->[enter] will bring you to the lists and in the L3 columnat the top we will enter another list this time its the probabilities of the pennies, easily calculated by pressing: [2nd]->[2]->[/](divide)->[3][0][0] at the top of the column and the calc does the rest

To plot this as a probability graph press [2nd]->[Y=] turn on plot 1 change to the 3rd type of graph (bar graph) then change Freq to L3 by pressing [2nd][3]

then press [window] change settings to:

Xmin=2.7

Xmax=3.5

Xscl=0.1

Ymin=-0.1

Ymax=0.35

Yscl=0.05

Pressing [graph] will show the graph in a nice pretty easy to read form

To make it a Frequency graph make Freq L2 instead of L3,

Ymin=-25 and Ymax=100

And the graph will a frequency graph instead

So thats it for all we learned, and the homework was p.108 #1-9

Happy Pi Day and I'll find that coin so everybody should give up :P

Later,

Shane

Scribe Tomorrow: Corrie

Today we learned some tricks for the TI-83's and it had to do with averages and probability (thus the name) so I'll try to recreate them as best as I can.

First we were given a list of 6 weights of potatoe sacks from 2 different farmers (6 each)

Farmer 1 | Farmer 2 |

49 | 40 |

51 | 60 |

48 | 45 |

52 | 55 |

47 | 35 |

53 | 65 |

To enter the numbers press:

[stat]->[enter]-> enter the data in the respective lists -> [2nd]->[mode]

When the numbers have been entered in the lists and all is complete we now can change the information into 1-Variable Statistics by pressing:

[stat]->[>](calc)->[1](1-var Stats)->[2nd]->[1](L1)->[enter]

The screen now displays the following info:

X=50 (average of list 1)

ƩX=300 (sum of all numbers on list)

ƩX

^{2}=15028 (all the numbers on the list squared then added up)SX=2.3664... (sample deviation)

őX=2.16024... (standard deviation)

n=6 (number of numbers on list)

minX=47 (minimum)

Q1=48 (inbetween minimum and middle)

med=50 (middle)

Q3=52 (inbetween middlde and maximum)

maxX=53 (maximum)

Pressing the same keys as before but replacing 2 for 1 like so:

[stat]->[>](calc)->[1](1-var Stats)->[2nd]->[2](L2)->[enter]

will give the results above but for list 2

X=50

ƩX=300

ƩX

^{2}=15700SX=11.83215957

őX=10.8012345

n=6

minX=35

Q1=40

med=50

Q3=60

maxX=65

Another thing we learned was how to put info into a probability graph

we used pennies as an example and thier weights.

f(frequency) | Mass(g) |

2 | 2.7 |

4 | 2.8 |

34 | 2.9 |

71 | 3.0 |

94 | 3.1 |

74 | 3.2 |

17 | 3.3 |

4 | 3.4 |

With this data now entered into the lists we press:

[stat]->[>]->[1]->[2nd]->[1]->[,]->[2nd]->[2]

This mulitplies the numbers together to create a result we wanted (to tell the probability of a penny of a certian weight happening)

X=3.087

ƩX=926.1

ƩX

^{2}=2863.35SX=0.1223

őX=0.12219

n=300

minX=2.7

Q1=3

med=3.1

Q3=3.2

maxX=3.4

Hitting [stat]->[enter] will bring you to the lists and in the L3 columnat the top we will enter another list this time its the probabilities of the pennies, easily calculated by pressing: [2nd]->[2]->[/](divide)->[3][0][0] at the top of the column and the calc does the rest

To plot this as a probability graph press [2nd]->[Y=] turn on plot 1 change to the 3rd type of graph (bar graph) then change Freq to L3 by pressing [2nd][3]

then press [window] change settings to:

Xmin=2.7

Xmax=3.5

Xscl=0.1

Ymin=-0.1

Ymax=0.35

Yscl=0.05

Pressing [graph] will show the graph in a nice pretty easy to read form

To make it a Frequency graph make Freq L2 instead of L3,

Ymin=-25 and Ymax=100

And the graph will a frequency graph instead

So thats it for all we learned, and the homework was p.108 #1-9

Happy Pi Day and I'll find that coin so everybody should give up :P

Later,

Shane

Scribe Tomorrow: Corrie

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