8.5(d) Scatter Plot Trend Line Predictions

Front

What is a trend line in a scatter plot?

Back

A trend line is a straight line that best represents the data points in a scatter plot, showing the general direction of the data.

Front

How do you use a trend line to make predictions?

Back

You can use a trend line to estimate values by finding where a specific x-value intersects the trend line and reading the corresponding y-value.

Front

What does it mean if the trend line slopes upwards?

Back

An upward slope indicates a positive correlation, meaning as one variable increases, the other variable also tends to increase.

Front

What does it mean if the trend line slopes downwards?

Back

A downward slope indicates a negative correlation, meaning as one variable increases, the other variable tends to decrease.

Front

What is the purpose of creating a trend line in a scatter plot?

Back

The purpose is to summarize the relationship between the variables and to make predictions based on that relationship.

Front

How can you determine the strength of a correlation from a scatter plot?

Back

The strength of a correlation can be determined by how closely the data points cluster around the trend line; tighter clustering indicates a stronger correlation.

Front

What is interpolation in the context of scatter plots?

Back

Interpolation is predicting a value within the range of the data points using the trend line.

Front

What is extrapolation in the context of scatter plots?

Back

Extrapolation is predicting a value outside the range of the data points using the trend line.

Front

If a scatter plot shows no clear trend, what does that indicate?

Back

It indicates that there is no correlation between the variables, meaning changes in one variable do not predict changes in the other.

Front

What is the formula for calculating the slope of a trend line?

Back

The slope (m) is calculated as m = (y2 - y1) / (x2 - x1) using two points (x1, y1) and (x2, y2) on the line.