Statistics

Spurious Correlations

Correlation does not imply causation, kids.

Quiz Thursday 10/31:

•Writing a regression equation from computer output

•Making a prediction

•Calculating a residual

•Determining when model over- or under- estimates a data point

•Reading a residual plot

Below is a practice quiz with answers and explanations:


LSRL and residuals ANSWER KEY.docx

Below is a practice quiz with answers and explanations. [The only thing missing is sketches of the normal distribution.]

The actual quiz will be on Thursday 10/10

zscores and percentiles answer key.docx

z-scores, Normal distributions, and percentiles

Where to find notes and examples in the textbook:

Any Distribution

•Standardizing and unstandardizing scores (page 86)

Normal distributions

•Find the percentage when you know the z-score (page 84)

•Find the z-score when you know the percentage (page 85)

•Standardizing scores (page 86)

•Interpreting z-scores (page 87)


Homework:

Page 93+: –E59, 61, 62, 63, 64, 65

Standard Deviation Spreadsheet for TBA Lesson:

https://docs.google.com/spreadsheets/d/10tAGane39Rk8a367j_SzjyX6z99vjov1l7xl5naGuv0/edit?usp=sharing

  1. Sign in to your Google account.
  2. Make a copy of the spreadsheet so you can edit it.
  3. Find the standard deviation for the class data.


Bureau of Justice Statistics Website for 9/19/19 Lesson:

  1. Pick two states, a type of crime, and a range of years.
  2. Download the data as a spreadsheet.
  3. Make a histogram, find the 5-number summary, mean, IQR, and standard deviation for each state.
  4. Describe and compare the distributions in terms of shape, center, and spread.
  5. Save this information in a file and email to me at kheinri@tacoma.k12.wa.us


mean = AVERAGE(cell range)

standard deviation = STDEV(cell range)

minimum =MIN(cell range)

first quartile =QUARTILE.INC(cell range, 1)

median =QUARTILE.INC(cell range, 2)

third quartile =QUARTILE.INC(cell range, 3)

maximum =MAX(cell range)


Quiz Next Tuesday (9/17)

•Know what sample, statistic, population, and parameter mean, and how to identify them in context

•Know what counts (and does not count) as a random process

•Know the definition of bias

•Be able to identify if a method is biased or unbiased from a sampling distribution

•Know what size, voluntary response, convenience, undercoverage, nonresponse, and questionnaire bias are, and be able to identify them in context.

•Know what a simple random sample is, and how you could design one to select a sample

Quiz Review (Questions first, then answers provided later in the document)

Survey methods review fall 2019.docx

Survey Data

Survey Results (P-A).xlsx

Types of Bias Notes

random and biased sampling notes and practice 2014.docx

PowerPoint Notes

Survey Methods Notes from Powerpoint.docx