Probability
What is the fractional probability of landing on "heads" when flipping a fair, two-sided coin.
1/2 or 50%
What is a Confidence Interval?
This term refers to the range of values.
This hypothesis is the starting assumption that there is no change, no effect, or no difference between the groups being studied.
Null hypothesis or Ho
What is the name for the straight line drawn through a scatter plot that summarizes the relationship between the two variables.
Line of best fit or least squares regression line.
What is the sampling method that involves assigning every member of a population a number and using a random number generator to select participants.
Random Sampling.
If you roll a standard six-sided die, what is the probability of rolling a specific number, such as a 4.
1/6
What is the Normal Distribution?
A bell shaped curve that is used to find critical values when the population standard deviation is known and the sample size is large.
Often set at 0.05, this Greek letter represents the probability of rejecting the null hypothesis when it is actually true.
The alpha/significance level.
In the standard regression equation y= mx + b, the variable y represents the dependent variable, while the variable X represents...
The independent variable
To ensure diverse representation, a researcher divides a population into subgroups (like age or gender) and then samples randomly from each subgroup. This method is known as...
Stratified Random Sampling
A jar contains 5 red, 3 blue, and 2 green marbles. This is the probability of reaching in and picking a marble that is not red.
1/2 or 50%
To find the margin of error, you multiply the Standard Error by this value, which is determined by the confidence level.
Critical Value
If this value is less than your alpha level, you "reject the null hypothesis" because the observed result is unlikely to have happened by chance.
p value
This value, denoted as r , ranges from -1 to 1 and tells you how closely the data points follow a straight line.
Correlation Coefficient
This method is often used for geographic studies; researchers divide a city into blocks, randomly select five blocks, and then survey every single person living on those specific blocks.
Cluster Sampling
In a standard 52-card deck, what is the probability of drawing a Queen or a Spade.
16/52 or 4/13 or 33.7 percent
You calculate two intervals using the same data: one at 90% confidence and one at 99% confidence. Which of the two intervals will be wider
99% confidence
This type of error, also known as a "false negative," occurs when you fail to reject the null hypothesis even though the alternative hypothesis is actually true.
Type II error
Using the regression equation y=mx=b, = 3x + 10, what would be the predicted value of y if the x value is 5.
25
If a researcher selects every member from a list (for example, every 20th person walking into a mall), what method are they using?
Systematic Sampling
In a binomial experiment with 4 independent trials and a success rate of $p = 0.5$, this is the probability of getting exactly 3 successes.
1/4 or 25%
A researcher provides a 95% confidence interval for a population mean as (82, 98). If the sample size used was 100 and the population standard deviation was 40, what is the z-score (critical value) they used—which suggests they might have actually calculated a different confidence level than 95%?
2
If the null hypothesis states that a coin is fair (p = 0.5), what type of hypothesis would state that the coin is weighted, or p is equal to or less than 0.5$.
Alternative Hypothesis or Ha
What is the term that describes the difference between an actual observed data point and the value predicted by the regression line.
Residual.
This specific type of bias occurs when a sample consists of people who choose themselves to be part of the study. Because people with strong opinions are more likely to participate, the results rarely represent the general population.
Voluntary Response Bias