Context: Ancient tables provided the sun's mean longitude. Christopher Clavius, the architect of the Gregorian calendar, noted that the tables agreed neither on the time when the sun passed through the vernal equinox nor on the length of the mean tropical year. Tycho Brahe also noticed discrepancies. The Gregorian leap year rule (97 leap years in 400 years) was put forward by Petrus Pitatus of Verona in 1560. He noted that it is consistent with the tropical year of the Alfonsine tables and with the mean tropical year of Copernicus (De revolutionibus) and Reinhold (Prutenic tables). The three mean tropical years in Babylonian sexagesimals as the excess over 365 days (the way they would have been extracted from the tables of mean longitude) were 14,33,9,57 (Alphonsine), 14,33,11,12 (Copernicus) and 14,33,9,24 (Reinhold). All values are the same to two places (14:33) and this is also the mean length of the Gregorian year. Thus Pitatus' solution would have commended itself to the astronomers.

Question: Who was the architect of the Gregorian calendar?
Answer: Christopher Clavius

Question: What did the architects of the calendar notice about the astronomical tables?
Answer: discrepancies

Question: Whose solution to the discrepancies of the tables would have been agreeable to astronomers?
Answer: Petrus Pitatus

Question: When did Pitatus offer his solution to the leap year problem?
Answer: 1560

Question: What is the theory about leap year called?
Answer: Gregorian leap year rule

Question: What provided the sons mean latitude?
Answer: Unanswerable

Question: Who noticed that the tables agreed on the time the sun passed the vernal equinox?
Answer: Unanswerable

Question: Who suggested ninety-seven leap years in 400 years during the fifteenth century
Answer: Unanswerable

Question: Who solution to discrepancies in the tables was not agreeable to astronomers?
Answer: Unanswerable

Question: What calendar did Pitatus create?
Answer: Unanswerable