Question

(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?

Answer 1

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:
$Portion\text{ }of\text{ }threshold= \frac{Poverty\text{ }threshold\text{ }(World\text{ }Bank)}{Poverty\text{ }threshold\text{ }(U.S.)} *100\% \\ \\ Portion\text{ }of\text{ }threshold= \frac{1825}{29000} *100\% \\ \\ Portion\text{ }of\text{ }threshold=6.29\%$

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