Chapter 3
Data that has only one variable
Univariate Data
A line drawn on a scatter diagram that shows the trend followed by the data points. This line can then be used to make predictions.
Line of Best Fit
Ho and H1
Null and Alternative hypothesis
Press [STAT] to enter the statistics menu. Press the right arrow key to reach the CALC menu and then press 4: LinReg(ax+b)
Least Squares Regression Line
Statistical test that is used to compare two groups
t-test
Not a random sample
Biased Sample
A function whose graph is made up of line segments
Piecewise Functions
Checks whether two variables are likely to be related or not.
X2 test for independence
Turn on Stat Diagnostics. Put data into L1 and L2. Go to [STAT], [CALC], then 4
Pearson’s Product Correlation Coefficient (r)
Difference between X2 test for independence and X2 goodness of fit test
Goodness of Fit: hypothesized distribution
Independence: hypothesis states the variables are independent or not
The whole group from which you may collect data
Population
The line of best fit that has the smallest possible value for the sum of the squares of the residuals
Line of Regression
The ranks of a set of data
Spearman's rank correlation coefficient
STAT-edit, enter data, Stat-Calc-1VarStats-2nd-1
Standard Deviation
When do you reject null hypothesis?
If the chi square statistic is greater than the critical value
Selecting a random sample where numbers in certain categories are proportional to their numbers in the population
Stratified Sample
Is a measure of the linear correlation between two variables x and y and can take a value between −1 and 1 inclusive. It indicates how close the points fall to a straight line and whether the correlation is positive or negative
Pearson’s Product Correlation Coefficient (r)
Correctly inferred something from your data sample
Statistical inference
Press 'Stat' and enter the ranks into L1 and L2. (Make sure Stat Diagnostics are ON.) Then, press 'Stat' again, 'CALC', choose '4:LinReg(ax+b)' to find this value
R-Spearman's rank correlation coefficient
What do you do when you have tied values in Spearman's
Take the mean of the affected values and assign this rank to both tied values
Selecting a sample of eight boys and eight girls is an example of
Quota sampling
Not a direct relationship between what is being measured, but the data points may indicate a close relationship
Statistical Relationship
Multiply variables together, and then divide by the total people in the survey to make what
Expected frequency table
Press 2nd + x-1 to get to the matrix page, and then 'EDIT'. Once there, you put your observed values in '[A]' and your expected values in '[B]'. Go to 'Stat,' toggle to 'TESTS,' and select option 'C: X2-Test,' [Calc].
X2 test for independence
What is the difference between one-tailed and two-tailed tests?
One-tailed is measuring whether one mean is significantly larger than the other. Two-tailed is measuring whether the means are significantly different, without assuming one is larger than the other