Answer: 
Step-by-step explanation:
Given : The number of children in a family is 1, 2, 3, or 4.
Little Joe (a boy) has no brothers. But he may have sisters.
The sample space for the number of child in Joe's family : {B, BG, BGG, BGGG}, where G represents girl and B represents boys.
Then , for the probability that he is an only child, favorable outcome = B
Thus, the probability that he is an only child is given by :-

Hence, the probability that he is an only child = 
Answer:
2
Step-by-step explanation:
$138494.7
Step-by-step explanation:
170828-73828=97000
97000÷12=8083.3
8083.3= the amount the house depreciated every year
8083.3×4 =32333.3
170828-32333.3= $138494.7