The Mona Lisa has approximate dimensions 75 cm by 55 cm.

5) If we reduce the painting by a scale factor of 1:15, what are the dimensions of the reduction to the nearest hundredth of a cm?

To find the dimensions of the reduced painting, we need to divide the original dimensions by 15.

Height: 75 cm / 15 = 5 cm
Width: 55 cm / 15 = 3.67 cm

Therefore, the reduced dimensions of the Mona Lisa would be approximately 5 cm by 3.67 cm.