Nissan used a 4.4:1 final drive in 1.0 litre Micra's from about June 98 onwards
You can just about count the number of teeth on the crown wheel when looking through the drain plug. You need to count 76 teeth for the 4.4:1 final drive, if you count 74 you have a 3.8:1 final drive, if you count any other number, start again.