EXAMPLE 7 Interpreting the slope and the intercept

Interpret the following values of the regression line we obtained in Example 6:

  1. The intercept
  2. The slope

Solution

  1. In statistics, we interpret the slope of the regression line as the estimated change in y per unit increase in x. In our temperature example, the units are degrees Fahrenheit, so we interpret our value as follows:

    “For each increase of 1°F in low temperature, the estimated high temperature increases by 1.4°F.”

  2. The intercept is interpreted as the estimated value of y when x equals zero. Here, we interpret our value as follows:

    “When the low temperature is 0°F, the estimated high temperature is 8°F.”

NOW YOU CAN DO

Exercises 13b–24b.