2. Given the base period and growth amount, find the growth rate and current period.
3. Know the base period and growth rate, and find the growth amount and current period.
4. Know the current quantity and growth quantity, and find the base and growth rate.
5. Know the current quantity and growth rate, and find the cardinal number and growth amount.
6. Given the growth rate and amount, find the interval growth rate of the base period and the current period. ① Mixed growth rate is in the middle: the overall growth rate is between two local growth rates. ② The base period refers to the base period. In the problem, the current period is generally used to approximate the average proportion of the average annual growth and the average annual growth rate. 2. Geometric formula of quantitative relationship.