The equation of the line through the point (5,4) with a slope of 6/5 is y = 6/5x - 2. This is determined using the linear equation format y = mx + b. By substituting in the values, you can simplify to find the y-intercept.
To find the average daily change in temperature, total the four daily changes and divide the sum by 4:
(3.24, -0.375, -0.15, 0.778) / 4 results in about 0.87 degrees per day.