posted by Anonymous .
Median family income in country x between 1990 and 1999 can be modeled by f(x)=1144.7(x-1990)+35,834 where x is the year. Determine the median income was $42,303.
I did it this way don't know if it's right
42,303-35,834 = 1144.7 - (x-1990) + 35,834
6469. 1144 7 - (x-1990). 35,834
The median income was $1144.7 every year
Thanks for all your help:-)
The question was:
Determine when the median income was $42,303
Your answer does not fit the question. You started off right (I think). The posting is sort of garbled.
42303 = 1144.7(x-1990) + 35834
1144.7(x-1990) = 42303-35834
1144.7(x-1990) = 6469
x-1990 = 5.65
x = 1995.65
so, in late August 1995 the median income will be 42303.
You are sort of correct. The median income rises 1144.70 every year.
Since 42303 is 6469 more than the starting value of 35384, it takes 5.65 years to rise enough to reach the target value.