Do the Shiny app for the two-way table on sex and love_first.
How many times did you re-sample? 30,000
What percentage of the time did the re sampled chi-square statistic exceed the chi-square statistic in the actual study? 0.18%
Do you think there is overwhelming evidence that in the GC population the two sexes differ in whether they believe in love at first sight? Yes
Here’s the code for a chi-square test to see if sex and belief in love at first sight are related in the GC population. Run the code:
chisqtestGC(~sex+love_first,data=m111survey,
graph=TRUE)
## Pearson's Chi-squared test with Yates' continuity correction
##
## Observed Counts:
## love_first
## sex no yes
## female 22 18
## male 23 8
##
## Counts Expected by Null:
## love_first
## sex no yes
## female 25.35 14.65
## male 19.65 11.35
##
## Contributions to the chi-square statistic:
## love_first
## sex no yes
## female 0.44 0.77
## male 0.57 0.99
##
##
## Chi-Square Statistic = 2.0068
## Degrees of Freedom of the table = 1
## P-Value = 0.1566
Now look at the output and answer these question:
What’s the test statistic? 2.0068
About how big should it be if the Null is correct? 1
What’s the P-value? 0.1566
Are race and gun owndership related in the U.S. population? In the code chunk below, insert the code needed to use chisqtestGC() to investigate this question. Tip: copy-paste and then modify the code from the previous problem.
chisqtestGC(~race+owngun,data=gss02,graph=T)
## Pearson's Chi-squared test
##
## Observed Counts:
## owngun
## race No Yes
## AfrAm 106 16
## Hispanic 20 3
## Other 25 7
## White 454 284
##
## Counts Expected by Null:
## owngun
## race No Yes
## AfrAm 80.67 41.33
## Hispanic 15.21 7.79
## Other 21.16 10.84
## White 487.97 250.03
##
## Contributions to the chi-square statistic:
## owngun
## race No Yes
## AfrAm 7.96 15.53
## Hispanic 1.51 2.95
## Other 0.70 1.36
## White 2.36 4.61
##
##
## Chi-Square Statistic = 36.9779
## Degrees of Freedom of the table = 3
## P-Value = 0
Looking at the output, answer the following questions.
What’s the test statistic? 36.9779
About how big should it be if the Null is correct? 3
What’s the P-value? 0
Do you think we have strong evidence for a relationship in the population, or could the pattern in the data be due just to chance? Yes there is a strong evidence for a relationship in the population.
Do you think we have strong evidence for a relationship in the population, or could the pattern in the data be due just to chance?
Try simulation on the sex and seating-preference study:
chisqtestGC(~sex+seat,data=m111survey,
simulate.p.value="random",
B=3000)
Now try it again, without simulation:
chisqtestGC(~sex+seat,data=m111survey)
Compare the P-values: are they about the same, or very different?