Answer:
B. 
Step-by-step explanation:






Answer: option D
Step-by-step explanation:
The formulae for standard error = standard deviation/√n
But population standard deviation = 1.8 and sample size = n = 81
Standard error = 1.8/√81 = 1.8/9 = 0.2
Step-by-step explanation:
Sorry I cant get any more answers but I really hope that this helps
Answer:
C. 20
Step-by-step explanation:
Answer:
60°
please look into the solution down here.
Step-by-step explanation:
since BD bisects it, then the angles should be bisected symmetrically, or in other words, ANGLE ABD = angle DBC,
hence,
4x = 2x +30
2x = 30
x = 15
therefore, angle DBC = 2x + 30 = 2(15) + 30 = 60°.