the man was born in year 1998
Step-by-step explanation:
From the table, the difference in years the comet was seen is 7 years
1956-1949 = 1963 - 1956 = 1970-1963 = 7 years
If the next time the comet appeared was 2005 and a man born during an unknown year was the previous time the comet was seen, then the year the man was born will be the difference between year 2005 and the common difference.
The year the man was born = 2005 - 7years = 1998
To check that the answr is correct: if the man was born in 1998, the next time the comet would be visible after the man's birth is in 7 years time = 1998 + 7 = 2005
Therefore, the man was born in year 1998