Scatter Plots and Lines of Fit

The video tutorial covers scatterplots and lines of fit. It explains how scatterplots show relationships between data sets and the types of correlation: positive, negative, and none. The tutorial also demonstrates how to read scatterplots, identify outliers, and use lines of fit to make predictions. Practical examples are provided to illustrate these concepts, including calculating slopes and interpreting y-intercepts.

What type of correlation is shown when both variables increase together?

• No correlation

• Positive correlation

• Negative correlation

• Inverse correlation

Which of the following describes a non-linear trend in a scatterplot?

• A straight line

• A vertical line

• A horizontal line

• A curve or arc

In a scatterplot, what is an outlier?

• A point that is far from the trend

• A point that is at the origin

• A point that fits the trend

• A point that is on the x-axis

What is the first step in writing the equation of a line of fit?

• Draw a line through the data

• Identify two points on the line

• Make a scatterplot of the data

• Calculate the y-intercept

How do you determine the slope of a line of fit?

• By finding the y-intercept

• By subtracting the x values from the y values

• By dividing the change in y by the change in x

• By adding the x and y values

What does the y-intercept represent in the context of a line of fit?

• The minimum value of the independent variable

• The maximum value of the dependent variable

• The rate of change of the independent variable

• The starting value of the dependent variable

If a line of fit has a slope of 2,500, what does this indicate about the data?

• The dependent variable decreases by 2,500 units

• The dependent variable increases by 2,500 units for each unit increase in the independent variable

• The independent variable increases by 2,500 units

• The independent variable decreases by 2,500 units

What is the predicted salary of a salesperson after 15 years of employment, according to the line of fit?

• $100,000

• $50,000

• $70,000

• $90,000

Why might the y-intercept be irrelevant in some scatterplot analyses?

• It does not relate to the context of the data

• It always represents a negative value

• It is always zero

• It is always the same as the slope

What is the purpose of using a line of fit in data analysis?

• To eliminate outliers

• To predict values outside the collected data set

• To find the exact values of data points

• To create a perfect correlation