It is then, because then is used in chronological order, what is written is talking in chronological order(one thing after another). than is introducing a second element in a comparison
Which word is the italicizes word? the preposition of the sentence would be in, pronoun is not there, conjunction is not there and the linking verb i believe is and or were
Ten thousand value here is
45,122. Since the number proceding it is x

5, the answer will be rounded up by adding a number to 4 (Ten thousand value). Which is 50,000