Actually, wrong, and that chart is wrong. In engineering terms, and this is also how wheels are measured, a bolt circle is the diameter of a circle that goes through the center of all the bolts that lie on the circle perimeter.
A 5 on 4.5" bolt circle has five bolts (studs) whose center lie on a circle with a diameter of 4.5". The correct way to measure a 5 bolt circle is from the center of one stud, directly across the center of the circle to a the point where the opposite side of the circle would lie (with an odd number of studs this falls between two studs). With 4 or 6 studs you measure from the center of one stud to the center of the opposite stud, as they fall directly opposite each other on the circle.
That wheel has five studs which fall on a circle smaller than 4.5", it is most likely 5 on 4".
There is some bad information on the net, that diagram is an example.
