That depends on the resolution of the screen the pixel is on. An old tv has a lot less pixels than a modern wide screen computer monitor.
4 m = 400 cm
4 in = 4 x 2.54 cm = 10.16 cm
1 m = 100 cm so 4 m = 400 cm
.04 mm
10.16 cm
400 cm
4 feet is equal to 121.92 cm.
3 cm = 2 inches and 1/4
3 cm = 2 inches and 1/4
4 meters and 89 centimeters is equal to 489 centimeters
17.5 cm
1' is equal to approx 30cm