Answer: a.19.59% b.15.11%.
Explanation:
Average tax  rate is given as  the total tax paid divided by  total taxable income which is expressed as a percentage and must be less than the marginal tax rate.
Chandler is single and reports 
taxable income of $132,200. 
Tax liability: 25,903
 Marginal rate: 24 % 
Average rate: 17.94 x % = wrong
 Average rate = total liable tax/ total income= 25, 903/ 132,200=0.195937 rounded to 0.1959
0.1959 x 100 = 19.59%.correct
b. Lazare, a head of household, records 
taxable income of $80,600. 
Tax liability: 12,176 
Marginal rate: 22 %
 Average rate: 12.30 X %= wrong 
Average rate = total liable tax/ total income= 12,176/ 80,600= .0.15106= 0.1511
0.1511 x 100 = 15.11%.correct.