Choose
We calculate the expected counts in a Chi-Square GOF Test by _________.
multiplying the sample size by the given distribution's proportion
A Chi-Square statistic of 17.87 and a df of 6 would result in what p-value
p-value of ~0.006565
What is the shape of any Chi-Square distribution?
Skewed Right
We want to know if, in general, Summit and Livingston students get the same scores on their AP Statistics exams. We take separate samples from each building and compare the number who earn a 5, 4, 3, 2, or 1 on their test. We would use a __________.
Chi-Square Test for Homogeneity
A Chi-Square statistic of 30 and a df of 15 would result in what p-value?
p-value of ~0.0119
The larger the Chi-Square statistic, the __________ the p-value.
Smaller
One hint that a free response inference question is a Chi-Square test over a z- or t- test is if the data is given to us in a ____.
2-way table
Instead of checking for "random, normal, and independent," we replace one of these checks with a check for _________
Large Counts
We are testing whether or not the city of Waubun has the same age distribution as that of Ogema. Our Chi-Square value is 17.8, and our p-value is 0.003. Do we reject or fail to reject Ho?
Since our p-value (0.003) is less than our significance level of alpha=0.05, we must reject the null hypothesis. We do have sufficient evidence to suggest that there IS a difference between the distribution of age among Waubun residents and the distribution of age among Ogema residents.
Where is the peak of the Chi-Square distribution, in relation to the degrees of freedom?
The peak of the curve is always df-2.
EX: if the degrees of freedom is 7, the peak of the curve is at 5
The Random condition is met if _________ or _________.
the data come from a random sample(s) or the data come from a randomly assigned experiment
We ran a Chi-Square test to determine whether males or females traditionally score higher on their AP Statistics exams. We got a Chi-Square statistic of 3.72 and a p-value of 0.146. A complete conclusion (based on a significance level of alpha=0.05) is __________.
Since our p-value (0.146) is greater than our significance level of alpha=0.05, we must fail to reject the null hypothesis. We do NOT have sufficient evidence to suggest that there is a difference between the distribution of AP Statistics exam scores for males and the distribution of AP Statistics exam scores for females.
The distinction between a Chi-Square Test for Homogeneity and a Chi-Square GOF Test is comparable to the distinction between a Two-Sample Z-Test and a __________.
One-Sample Z-Test
If we are using CENSUS data to run a chi-square test, which conditions would we will skip?
-We would still note why we are skipping them in the check step, of course!
SKIP random and independent, STILL DO Large Counts
The formula for calculating a Chi-Square Test Statistic is __________.
𝛘2=Σ(observed - expected)2/(expected)
We want to determine whether or not musical preference among high school students has any influence on these students' preference of social media sites. The Chi-Square statistic was 18.7 and the p-value was 0.043. A complete conclusion (based on a significance level of alpha=0.05) is __________.
Since our p-value (0.043) is less than our significance level of alpha=0.05, we must reject the null hypothesis. We have sufficient evidence to conclude that there IS an association between musical preference and social media site preference.
I take ONE sample and ask TWO categorical questions. Which chi-square test(s) can I run based on this information alone?
Chi-Square test for Association or Independence