Answer:
Third option
Step-by-step explanation:
The first definition is not as broad as it should be, therefore, while an angle does meet that criteria, it's not a general definition, hence, it is incorrect. The second one is incorrect as well because a parabola has a vertex, and it is certainly not an angle. This definition is not specific enough, so it will be eliminated. The last one is again, too specific. The third one is the best answer because it is broad enough while still being specific.
Answer:
C 
Step-by-step explanation:
Consider the series
The nth term of series is 
The bottom index tells you that n starts changing from 3, so
Thus, the sum of all terms is
Answer:
2.5% probability that a randomly selected book has fewer than 133 pages.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 189 pages
Standard deviation = 28 pages
What is the probability that a randomly selected book has fewer than 133 pages?
133 = 189 - 2*28
So 133 is two standard deviations below the mean.
The Empirical Rule states that 95% of the measures are within 2 standard deviations of the mean. The other 5% is more than two standard deviations distant from the mean. The normal distribution is symmetric, which means that of those 5%, 2.5% are more than 2 standard deviations below the mean and 2.5% are more than 2 standard deviations above the mean.
This means that there is a 2.5% probability that a randomly selected book has fewer than 133 pages.
