(b) what portion of the official u. s. poverty threshold (roughly $29,000 for a family of four) is met by the world bank’s measure?

World Bank's threshold for poverty is $1.25 per person per day. 
For a family of four this gives:
Daily income = (number of people) * threshold
Daily income = 4 * $1.25
Daily income = $5
For a year this is:
Yearly income = (daily income) *365
Yearly income = $5 *365
Yearly income = $1825

U.S. poverty threshold is set at $29000. Portion of threshold can be calculated as:


The poverty threshold measured by World Bank is 6.29% of the U.S. poverty threshold.

The slope of the function is 0.5.