From 1950 to 1981 the amount of land cultivated for grain increased,
reaching an all time high in 1981 At that time, land previously
used for food production was shifted over to development and the
amount of land cultivated for grain and other agricultural uses
began to decline. The table below gives the amount of land cultivated
for grain for selected years, beginning in 1981. The units are
billion hectares (one hectare is about 2.46 acres)
Source: Wolrd Watch
- Use regression to find the linear function A(t) which best
fits the data in the table. Let t = 0 in the year 2000 so that
A(t) gives the area cultivated for grain, measured in billion
hectares, in year 2000 + t. Round your numbers to three decimal
Use the function A(t) to complete the remaining questions. Also,
save this function, it will be needed later.
- Predict the area cultivated in the year 2000.
- Estimate the number of years will it take for the area to
decrease by 0.100 billion hectares?
- How much will the area decrease in a two year period? How
does that compare with the actual change each two years as shown
in the data?
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