1. Which of the following function is associated with a continuous random variable?
a) pdf
b) pmv
c) pmf
d) all of the mentioned
Explanation: pdf stands for probability density function.
2. Statistical inference is the process of drawing formal conclusions from data.
a) True
b) False
Explanation: Statistical inference requires navigating the set of assumptions and tools.
3. The expected value or _______ of a random variable is the center of its distribution.
a) mode
b) median
c) mean
d) bayesian inference
Explanation: A probability model connects the data to the population using assumptions.
4. Point out the correct statement.
a) Some cumulative distribution function F is non-decreasing and right-continuous
b) Every cumulative distribution function F is decreasing and right-continuous
c) Every cumulative distribution function F is increasing and left-continuous
d) None of the mentioned
Explanation: Every cumulative distribution function F is non-decreasing and right-continuous.
5. Which of the following of a random variable is a measure of spread?
a) variance
b) standard deviation
c) empirical mean
d) all of the mentioned
Explanation: Densities with a higher variance are more spread out than densities with a lower variance.
6. The square root of the variance is called the ________ deviation.
a) empirical
b) mean
c) continuous
d) standard
Explanation: Standard Deviation (SD) is the measure of spread of the numbers in a set of data from its mean value.
7. Point out the wrong statement.
a) A percentile is simply a quantile with expressed as a percent
b) There are two types of random variable
c) R cannot approximate quantiles for you for common distributions
d) None of the mentioned
Explanation: R can approximate quantiles for you for common distributions.
8. Which of the following inequality is useful for interpreting variances?
a) Chebyshev
b) Stautaory
c) Testory
d) All of the mentioned
Explanation: Chebyshev’s inequality is also spelled as Tchebysheff’s inequality.
9. For continuous random variables, the CDF is the derivative of the PDF.
a) True
b) False
Explanation: For continuous random variables, the PDF is the derivative of the CDF.
10. Chebyshev’s inequality states that the probability of a “Six Sigma” event is less than ___________
a) 10%
b) 20%
c) 30%
d) 3%
Explanation: If a bell curve is assumed, the probability of a “six sigma” event is on the order of one ten millionth of a percent.