actually rate means anything divided by time......hope it helps
To find the percent of persons 65 and over with income below the poverty level in 1970, substitute t = 5 into the function P(t). For the rate of change, calculate the derivative of the function, P'(t), and evaluate at t = 5 to obtain the rate of change for the year 1970. ;
In 1970, approximately 21.44% of persons aged 65 and over had a family income below the poverty level. The rate of decline of this percentage was about 1.154% per year. This indicates that fewer seniors were living below the poverty line compared to earlier years.
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