Student or Learner
The baby weighed 11lb 5oz at birth.
an 11lb 5oz baby
He was 7ft 2in tall.
He was 7'2" tall.
a 7ft 2in man
a 7'2" man
His finishing time was 2hr 10min 33sec.
a 2hr 10min 33sec finishing time
a 2yr 5mo 2wk 4d project
The project lasted 2yr 5mo 2wk 4d.
No rewrites, please.
If the abbreviation is incorrect, please supply the correct one.
Can I use these abbreviations in formal writing ~ yes or no?
You should put a space between the number and the unit of measure. Except for degrees, percentages and the "quotation marks" used for feet and inches.
In the US, it is normal to put a period after abbreviations of units of measure.
I would not use " 7'2" " in formal writing. I would use "7 ft. 2 in."
A time like that would normally be expressed "2:10:33."
It is unlikely you wold find someone writing "a 2yr 5mo 2wk 4d project." If that level of precision is necessary, simply stating the number of years and days would suffice. If you really need to do it that way, then follow my advice from above above spaces and period.