Understanding Scatter Plots and Correlation

Miss Nance introduces scatter plots, explaining their purpose in showing relationships between data sets. She describes types of correlations: positive, negative, and no association. The strength of associations is discussed, along with linear and non-linear patterns. Miss Nance demonstrates using scatter plots for predictions with examples, such as the relationship between students and lunches, and hours worked versus pay.

What is the primary purpose of a scatter plot?

• To display individual data points without any relationship

• To calculate the average of a data set

• To compare more than two variables at once

• To show the relationship between two sets of data

Which type of correlation is indicated when both variables increase together?

• Negative correlation

• No correlation

• Positive correlation

• Inverse correlation

What does it mean when a scatter plot shows no association?

• The points form a perfect line

• The points are randomly scattered without a clear pattern

• The points are clustered tightly together

• The points form a curve

How can the strength of an association in a scatter plot be described?

• By the number of points

• By the size of the points

• By the distance between the points

• By the color of the points

What characterizes a linear scatter plot?

• The points are scattered randomly

• The points follow a straight line

• The points form a zigzag pattern

• The points form a circular pattern

In the example of students and lunches, what type of correlation is expected?

• Inverse correlation

• Negative correlation

• Positive correlation

• No correlation

What is the first step in making predictions using a scatter plot?

• Calculate the average of the data points

• Draw a trend line through the points

• Count the number of data points

• Identify the highest and lowest points

How do you determine the predicted value for a given input using a trend line?

• Count the number of points above the trend line

• Find the input on the axis and draw a line to the trend line, then across to the other axis

• Calculate the slope of the trend line

• Measure the distance between the points

If a person earns $300, how many hours did they likely work according to the trend line example?

• 20 hours

• 35 hours

• 25 hours

• 30 hours

What is the significance of a trend line in a scatter plot?

• It separates the data into two equal halves

• It highlights the outliers in the data

• It indicates the general direction of the data

• It shows the exact values of the data points