What is the arithmetic mean of the following numbers?
9, 10, 6, 5, 6

7.2

Step-by-step explanation: Mean= (sum of observations/number  of observations)

=(5+6+6+9+10)/5

=(36)/5

=7.2

δabc ≅ δdcb by sas because

db ≅ ac . . given (side)

bc ≅ bc . . reflexive property (side)

∠dbc ≅ ∠ acb . . alternate interior angles where transversal bc crosses parallel lines bd and ac (included angle)