Student or Learner
A survey by the national council of Churches showed that in 1986 there were 20,736 femaleministers, almost 9 percent of the nation's clergy,a number double that of 1977.
Is there any error in this sentence-specially with usage of that in the last part of the sentence
Also if the usage of "that" is correct then what is it funtioning as (relative pronoun, pronoun, conjunction etc)
No, the sentence is fine, Adnan. That 'that' means "the number".
... a number double the number of 1977.
a number that is double the number of female ministers that there was in 1977.