In January, Ms. NW projects that her employer will withhold $25,000 from her 2017 salary. However, she has income from several other sources and must make quarterly estimated tax payments. Compute the quarterly payments that result in a 2017 safeharbor estimate assuming that:
a. Her 2016 AGI was $176,000, and her tax was $47,200.
b. Her 2016 AGI was $139,000, and her tax was $36,800.