Random Vs Systemaic Error

12 Inch Battery Wall Clock Battery Wall Clocks Small Battery Wall Clock Large Battery Wall Clocks Sharp Atomic Wall Clock Sharp Digital Atomic Wall Clock Sharp 14 Inch Atomic Wall Clock Lighted Wall Clock Battery Stainless Steel Digital Wall Clock Large Atomic Digital Wall Clock Timex Wall Clock 24 Atomic Wall Clock Westclox Electric Wall Clocks Wall Clock With Battery 18 Inch Silent Wall Clocks 30 Inch Atomic Wall Clock 12 Inch Atomic Wall Clock Rectangular Wall Clocks Battery Operated Lighted Atomic Digital Wall Clock 120 Volt Wall Clock