A day of classy review
This presentation is the property of its rightful owner.
Sponsored Links
1 / 13

A Day of Classy Review PowerPoint PPT Presentation


  • 101 Views
  • Uploaded on
  • Presentation posted in: General

A Day of Classy Review. Shifting and Scaling. SAT/ACT Max SAT: 1600 (old school) Max ACT: 36 SAT = 40 x ACT + 150. ACT Summary Stats: Lowest = 19 Mean = 27 SD = 3 Q3 = 30 Median = 28 IQR = 6 Find equivalent SAT scores. SAT and ACT. ACT Summary Stats: Lowest = 19 Mean = 27 SD = 3

Download Presentation

A Day of Classy Review

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


A day of classy review

A Day of Classy Review


Shifting and scaling

Shifting and Scaling

  • SAT/ACT

  • Max SAT: 1600 (old school)

  • Max ACT: 36

  • SAT = 40 x ACT + 150

  • ACT Summary Stats:

  • Lowest = 19

  • Mean = 27

  • SD = 3

  • Q3 = 30

  • Median = 28

  • IQR = 6

  • Find equivalent SAT scores


Sat and act

SAT and ACT

  • ACT Summary Stats:

  • Lowest = 19

  • Mean = 27

  • SD = 3

  • Q3 = 30

  • Median = 28

  • IQR = 6

  • SAT = 40 x ACT + 150


Normalcdf

NormalCDF

  • The NormalCDF( function finds the percent of the total area of the distribution that falls between two z-scores.

  • For example, what would the

    NormalCDF(-1,1) be?

    (Hint: 68-95-99.7 rule)


Normalcdf procedure

NormalCDF Procedure

  • First, determine the type of question being asked

  • Once you’ve determined it is appropriate to use the NormalCDF function, convert given values into z-scores


Normalcdf1

NormalCDF

  • Questions:

  • What percent of the distribution falls between X and Y?

  • What percent of the distribution is greater than Y?

  • What percent of the distribution is less than X?

  • Answers:

  • NormalCDF(X,Y)

  • NormalCDF(Y,99)

  • NormalCDF(-99,X)


Invnormal going the other way

invNormal( Going the Other Way

  • The invNormal( function finds what z-score would cut off that percent of the data

  • Example: What z-score cuts off the top 10% in a Normal model? The bottom 20%?

  • The trick here is figuring out what percent (as a decimal) to enter in to the function.

  • Imagine invNormal calculates the area starting at -99.

  • So to find the z-score that cuts off the top 10% we want the z-score that includes 90%

  • invNormal (.9) = 1.28


Invnormal example

invNormal( Example

  • Based on the model N(1152, 84) describing angus steer weights, what are the cut-off values for

  • A) highest 10%

  • B) lowest 20%

  • C) middle 40%

  • A) invNormal(.9) = 1.28

  • B) invNormal(.2) = -.842

  • C) invNormal(.3) = -.524

    invNormal(.7) = .524

  • 1,259lbs

  • 1,081lbs

  • 1,108 – 1196lbs


New topic normal probability plots

New Topic – Normal Probability Plots

  • How to decide when the normal model (unimodal and symmetric) is appropriate:

  • Draw a picture (Histogram)

  • Draw a picture! (Normal Probability Plot)

  • A Normal Probability Plot is a plot of Normal Scores (z-scores) on the x-axis vs the units you were measuring on the y-axis (weights, miles per gallon, etc.)

  • A unimodal and symmetric distribution will create a straight line


What it looks like

What it Looks Like


What it looks like1

What it Looks Like


How it works

How It Works

  • A Normal probability plot takes each data value and plots it against the z-score you would expect that point to have if the distribution were perfectly normal

  • These are best done on a calculator or with some other piece of technology because it can be tricky to find what values to “expect”


Page 136 141 3 5 12 17 28 30

Page 136-141

# 3, 5, 12, 17, 28, 30

Homework


  • Login