Chi-Squared
When do you use a Chi-squared test?
What is when looking for the difference between your observed and expected values of a data set?
What is the abbreviated phrase "ME", the max expected difference the true population parameter and the sample estimate?
What is Margin of Error?
A sampling method where the population is divided into similar groups, and a random sample is chosen from each group.
What is Stratified Random Sampling?
Given a standard deck of 52 cards, what is the probability that a randomly selected card is a Queen, given that the card is black?
What is 2/26, 1/13, or ~0.077?
The probability of rejecting the null hypothesis when it is actually true.
What is a Type I Error?
How do you calculate the degrees of freedom?
What is the number of categories - 1
A 95% confidence interval for a mean, such as 4.5 to 4.8, indicates that one is 95% confident that this, rather than the sample mean, lies within that range
What is the true population parameter (or true population mean)?
This type of bias occurs when some members of the population are left out of the process of choosing a sample.
What is Undercoverage?
If events A and B are independent, and P(A) = 0.20 and P(B) = 0.39, what is (A and B)?
What is 0.078 (0.20*0.39)
The type of significance test used for the mean of a single population when the standard deviation of the population is unknown.
What is a T-test?
What are the 3 different types of Chi-squared tests?
What is GOF, Independence, and Homogeneity?
To compute a 95% confidence interval for a proportion, this \(z\)-critical value (rounded to two decimal places) is used.
What is z = 1.96?
According to the Central Limit Theorem, this is the approximate shape of the sampling distribution of the sample mean when the sample size n is large (n>_ 30), regardless of the population shape.
What is Approximately Normal?
A fair 6-sided die is rolled 60 times. What would the expected count be of each outcome? (?/60)
What is 60?
The three main conditions need to be verified for parametric inferential statistics.
What is Random, Independent, and Normal?
What is the equation of Chi-square?
What is x²= Sigma (observed-Expected)²/Expected
If you decrease the confidence level from 95% to 90%, the width of the resulting confidence interval will do this.
What is become narrower (or decrease)?
The numerical value that describes a characteristic of a sample, rather than the entire population.
What is a Statistics?
If the heights of students at CWHS are approximately normal, with a mean of 52 inches and a standard deviation of 4.7 inches, this is the calculator command used to find the probability that a student is taller than 60 inches.
What is normalcdf (60,1e99,52,4.7)?
This test is used to determine if two categorical variables on the same subjects are related.
What is a Chi-squared test for independence?
What is the Ho and the HA in the context of a Chi-squared test?
What is the Ho is no difference in the distribution of a categorical variable for several populations of treatments, and HA there is a difference in the distribution of a categorical variable for several populations of treatments?
To cut the margin of error for a confidence interval in half, you need to increase your sample size by approximately this factor.
What is quadruple (or \(\times 4\))?
This sampling technique divides the population into groups, randomly selects some groups, and surveys all individuals within those chosen groups.
What is Cluster Sampling?
You guess on a 30-question multiple-choice test (choices A-D). Using binomial probability, what is the probability of getting exactly 5 questions correct?
What is binompdf(30,0.25,5) ~0.1047?
The phrase used to describe an observed effect so large that it would rarely occur by chance.
What is statistically significant?