[CFA错题笔记11-Quantitativemethods]
本次做的题目是bookshelf 的R10（common probability distribution）、R11（sampling and estimation)，共66道题，下面分享14道错题：
R10 common probability distribution
3.The value of the cumulative distribution function F(x), where x is a particular outcome, for a discrete uniform distribution:
A.sums to 1.
B.lies between 0 and 1.
C.decreas as x increas.
正
确
答
案
：
B
考点：R10 2. DISCRETE RANDOM VARIABLES
A probability function has two key properties (which we state, without loss of generality, using the notation for a discrete random variable):
•0 ≤p(x) ≤ 1, becau probability is a number between 0 and 1.
【Doris 叨叨】
题目大意：
累积分布函数，对于离散型分布的概率是
由考点得知B正确，，，，，，，我眼瞎看错选项。。。。。
6.Over the last 10 years, a company’s annual earnings incread year over year ven times and decread year over year three times. You decide to model the number of earnings increas for the next decade as a binomial random variable.
A.What is the probability that earnings will increa in exactly 5 of the next 10 years?
B.Calculate the variance and standard deviation of the number of yearly earnings increas during the next 10 years.
正
确
答
案
：
A.10.3%
B.2.1和1.449
考点：R10 2.2. The Binomial Distribution Equation (1)
p
(
x
)
=
P
(
X
=
x
)
= (
n
x )
p
x
