a)
The population in 2011 is that of 2010 plus 1.1% (=0.011) of the population in 2010; therefore
The answer to the first gap is 6.98.
Similarly, in the case of 2012,
The answers to the second row of gaps are 2 and 7.05 (2 years after 2010 and 7.05billion).
Finally,
The answers to the third row of gaps are 3 and 7.13
b)
Notice that the pattern below emerges from the table in part a)
Thus, the exponential equation that models the population is
The answer to part b) is 6.9(1.011)^t
c) 2020 occurs 10 years after 2010; therefore, setting t=10 in the equation found in part b)
The rounded answer is 7.70