Tax form Schedule A question

Need help filling out line 5 (line 5b in particular), using the given information. Explanation of answer and any necessary calculation is much appreciated

Jordan (SSN 150-66-7788) and Diana (SSN 150-67-4321) Diego are a married couple who reside at 111 Coral Drive in Miami, FL 33156. They have one dependent daughter, Emily (SSN 155-88-4321), age 18, who lives at home. Jordan is a manager at Big Box Corporation. His form W-2 wages are $88,000 and federal income tax withheld is $13,200. The correct payroll taxes were withheld. Diana worked at a local department store for the first half of the year. Her Form W-2 wages are $45,000 and federal income tax is $3,500. The correct payroll taxes were also withheld. The Diego family paid $15,200 interest on their home mortgage (reported to them by the mortgage company on Form 1098). The Diego family also owns a vacation home in Breckenridge, Colorado, for which they paid $4,100 of mortgage interest. (This is qualified mortgage interest for a second home). The Diego family paid real estate taxes on their principal residence of $5,400, $2,000 of real estate taxes on their vacation home and $3,200 of sales taxes during the year. The vacation home in Breckenridge was rented out for 120 days during the year for which they received $12,000 in rental income. Jordan and Diana made significant decisions such as approving new tenants while a local management company handled the day-to-day needs. The Diego family used it for 30 days for a personal vacation during the year. Other expenses for the year for this vacation home (excluding interest and taxes mentioned above) were: $700 for real estate management fees paid to a local agent who handles the rental of the property, insurance expense $2,200, repairs expense $500, and utilities expense $1,800. Their depreciation expense for the rental use of this property for the year is $1,455. They use the IRS formula for allocating interest and taxes. The Diego family contributed $4,000 cash to their church and they have the necessary documentation for this contribution. i Aloon che le