Answer:

Step-by-step explanation:

The answer is a vertex. Corners of any shape are vertexes
The correct answer is B. Most patients who have a poor dental experience also have post-extraction complications. This can be shown through the fact that of everyone who had a poor dental experience, 94% said they had post-extraction complication. 94% is obviously <em>most</em>. We can not confidently say that poor dental experiences cause post-extraction problems because we do not know how many people who had a normal or good experience also had problems.
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