So, I checked Keith's height and weight. He's 3 years and 3 months old... 36.5" (just a smidgen over 3 feet) and 28.8 lbs. That puts him around the 10th percentile for his height and still under the 5th percentile for weight.
Mitchell is 25" long and about 12.8 lbs. That puts him at about the 25th percentile for weight and the 75th for length.
When Keith was 2 months old, he was 10 lbs 14.75 oz and 22.5" long, putting him between the 10th and 25th for both. At 4 months, he was 16.5 lbs (50-75th percentile) and 26.25" (75-90th percentile). He wasn't measured at 3 months, but it was obviously somewhere in the middle of all this, right?
I am questioning some of Keith's past dates and therefore his percentiles. I don't recally Keith EVER being above the 25th percentile in ANYTHING, but I'll edit this if I need to later!