I have tried to figure out part A and C for the past three days.

I have provided the excel sheet as well with the formulas that I used. Could someone answer this question with a step by step process so I know where I went wrong.

Please!!!! THANK YOU!!!!

Mary Jarvis is a single individual who is working on filing her tax return for the previous year. She has assembled the following relevant information: - She received $119,000 in salary. - She received $16,000 of dividend income. - She received $6,200 of interest income on Home Depot bonds. - She received $22,500 from the sale of Disney stock that was purchased 2 years prior to the sale at a cost of $6,500. - She received $12,500 from the sale of Google stock that was purchased 6 months prior to the sale at a cost of $5,500. - Mary receives one exemption ($4,000), and she has allowable itemized deductions of $7,500. These amounts will be deducted from her gross income to determine her taxable income. Assume that her tax rates are based on Table 3.5. The data has been collected in the Microsoft Excel Online file below. Open the spreadsheet and perf analysis to answer the questions below. Open spreadsheet a. What is Mary's federal tax liability? Round your answer to the nearest cent. Do not round intermediate calculations. $ b. What is her marginal tax rate? Round your answer to 1 decimal place. % c. What is her average tax rate? Round your answer to 2 decimal places. %