Chapter 3 - Terms
The exponential random variable is bounded below by _____ .
0
The probability that a continuous random variable X assumes a particular value x is ______ .
0
The area under a normal curve below its expected value is _____ .
0.50
How many parameters are needed to fully describe any normal distribution?
2
The probability that the normal random variable Z is less than 1.5 is equal to ______ .
P(Z> -1.5)
The exponential distribution is related to __________ distribution.
Poisson
T/F: The empirical rule should be applied to data sets that are normally distributed or approximately normally distributed.
T
The letter used to denote a standard normal random variable is ____ .
X
The summary values for grouped data are _________ values.
approximate
The ________ is best described as a relative measure of dispersion.
coefficient of variance
What is the most widely used measure of central location?
mean
A normal distribution is ________ around its mean.
symmetric
A continuous random variable is characterized by _______ value because
uncountable
The exponential distribution is based entirely on ______ parameter(s).
1
The height of the probabitity density function f(x) of the uniform distribution defined on the interval [a,b] is ______ .
1 / (b - a)
T/F: Mean-variance analysis suggests that investments with lower average returns are also associated with higher risks.
F
T/F: The distinct values of both a continuous random variable and a discrete random variable can be counted.
F, a continuous random variable assumes an infinite number of values over an interval.
T/F: The expected value and the variance of the standard normal variable Z are both 0.
F, the expected value of Z is 0, but its variance is 1.
Is it possible for the data to have no mode?
Yes, if there are no observations that occur more than once.
The shape of a graph depicting the normal probability density function is _______ .
bell shaped
The probability that a discrete random variable X assumes a particular value x is ________ .
between 0 and 1
A sample statistic is considered ________ if it systematically over or under-estimates the unknown parameter being estimated.
biased
The ________ allows us to use the normal probability distribution to approximate the sampling distribution of the sample mean whenever the sample size is large.
central limit theorem
__________ sampling works best when most of the variation in a population is within groups and not between groups.
cluster
Normal random variable is an example of a _________ random variable.
continuous
A random variable x with an equally likely chance of assuming any value within a specified range is said to have a __________ distribution.
continuous uniform distribution
The _________ describes both the direction and the strength of the linear relationship between two random variables.
correlation coefficient
Discrete random variable x assumes a _______ number of distinct value.
countable
The numerical measure that reveals only the direction of the linear relationship between two variables, but the not the strength of the linear relationship, is referred to as _________.
covariance
If X is a normally distributed random variable, then the mean, median, mode and are all _____ .
equal
When a sample statistic is used to make inferences about a population parameter, it is referred to as ________ .
estimator
We use the _________ population correction factor to reduce the sampling variation xbar and pbar.
finite
The branch of statistics that uses sample statistics to estimate a population parameter or test a hypothesis about such a parameter is best referred to as _________ .
inferential statistics
What is the primary requirement for a 'good' sample?
it is representative of the population we are trying to describe
The z table provides the cumulative probabilities for a given z. What does 'cumulative probabilities' mean? The probabiity that Z is ______ to given z value.
less than or equal
The probability distribution of a discrete random variable is called it probability _______ .
mass function
MAD ( _________ ) is denominated in the same units as the original data.
mean absolute deviation
Generally, the ___________ is the best measure of central location.
median
The ________ distribution is continuous and symmetric in shape.
normal
The exponential distribution is ______.
not symmetric
A parameter is a numerical measure that describes a sample of population?
population
Stratified sampling is preferred to cluster sampling when the objective is to increase __________
precision
A simple random sample is a sample of observations that is ______________ of the population from which is was chosen.
representative
The Sharpe ratio determine the additional __________ an investor will receive for each additional unit of risk taken.
reward
Mean-variance analysis is used to measure the performance of an asset based on its rate of return. Specifically, evaluating the rate of return on the basis of ________.
risk and reward
__________ bias occurs when there is a systematic exclusion of certain groups from consideration for the sample.
selection
__________ bias occurs when those responding to a survey or poll differ systematically from the non-respondents.
selection
The ________ is the positive square root of the variance.
standard deviation
In _________ sampling, the population is divided up into mutually exclusive and collectively exhaustive groups called strata. The sample consists of elements from each stratum.
stratified random
If we were to sample repeatedly from a given population, the average value of the sample means will equal ______ .
the population mean
In a mean-variance analysis using risk and reward, the measure associated with risk is the __________ , and the measure associated with reward is the __________ .
variance, mean