Formulas
Chi Square
Chi Square Tables
Reliability / Validity
100

Play the video from 1:00-1:10.

Use the formula to determine df.

 


df = (R-1)(C-1) = (4-1)(2-1) = (3)(1) = 3

100

What is the difference between the three below?

 

X squared

chai tea

chi squared

100

Part a. List the observed frequencies.

Part b. State N.

a. 23, 6, 1, 23

b. N = 53

100

This is the formula for predictive validity / explained variance as a percent.

r2x100

200

Formula for fe

200

What do fo and fe stand for?

observed frequency & expected frequency

200

What is the difference between obtained chi square and critical chi square?

obtained chi square is the value calculated based on the data

critical chi square is a cut-off value on a chart used to determine significance


200

A personality test is designed to determine how well two people match romantically.  r = 0.7.  What is the predictive validity / explained variance as a percent?

49

300

draw a chi square matrix for which df would not equal 1

Any matrix other than 2 x 2

300

10 students were drinking Chai tea while solving chi square problems.  All 4 students with glasses solved the problem correctly and all 6 students without glasses solved the problem incorrectly.  Is wearing glasses related to the ability to solve a chi square problem?

Yes

300

If = .04, the confidence level is ___%.  Fill in the blank AND state whether the variables are or are not significantly related.

96% and significantly related

300

Mr. Serling puts an Anatomy question on his final exam.  His exam could be criticized because it is considered not ____.   Use an appropriate Statistics term to fill in the blank.

valid

400

Formula for obtained chi squared (not the 2 x 2 shortcut formula)


400

In a chi square matrix, the row totals are 10 & 15 and the column totals are 12 & 13.  What is N?

25

400

What p-value indicates 99% confidence?

p = .01

400

The October and November SATs are designed to be equally difficult so that student scores are consistent. The SAT does a poor job predicting what it is designed to: first year college grades. Based on this information, is the SAT reliable, valid, both or neither?

reliable

500

Chi square by hand shortcut formula for 2 X 2 matrix

500

The observed and expected frequencies are equal.  Determine the numerical value of obtained chi square.

0

500

Draw a chi square matrix for which the df = 6.

500

The predictive validity / explained variance between two variables is 64%. List the possible value(s) of r.

0.8 and -0.8

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