the table lists how poverty level income cutoffs (in dollars) for a family of 4 have changed over time. Use the midpoint formula to approximate the poverty level cutoff in 1987 to the nearest dollar.://// 1970-3753

1980-8133
1990-13756
2000-17329
2004-19406

1 answer

Not sure what your midpoint formula is, but since 1987 is 7/10 of the way from 1980 to 1990, I'd interpolate to get
8133 + 0.7 (13756-8133) = 12069