We are shown the image of a line with marked points (167, 75) and (86, 30)
The y axis is the temperature in degrees Centigrade, and the horizontal axis the temperature in degrees F.
We are asked to find the slope of the line, for which we use the slope formula:
slope = (y2 - y1) / (x2 - x1)
in our case:
slope = (75 - 30) / (167 - 86) = 45 / 81 = 5 / 9
where we simplified a common factor of 9 in the fraction.
The slope is positive, and means the ratio between the degrees C and the degrees F meaning 5 degrees C per 9 degrees F.
So in the second box you need to type "9" . because every 5 C there is a 9 degree change in F.