Stats- C4

Question 1

Given n sorted data points, how do we calculate Q1,Q2 and Q3

P14

Answer 1

Q1 = 1(n + 1)/4th value
Q2 = 2(n + 1)/4th value
Q3 = 3(n + 1)/4th value

Question 2

What does the binomial distribution measure?

P15

Answer 2

The binomial distribution measures the probabilities of the number of successes over a given number of trials with a specified probability of success in each try.

Question 3

What does the poisson distribution measure?

P16

Answer 3

The Poisson distribution measures the likelihood of a number of events occurring within a given time interval, where the key parameter that is required is the average number of events in the given interval (l).

Question 4

In normal distribution, the symmetry of deviations leads to zero ____ and the low probabilities of large deviations from the central value reveal themselves in no ____.

P17

Answer 4

skewness
kurtosis

Question 5

In log-normal distribution, as the sigma rises, the peak of the distribution shifts to the left and the skewness in the distribution increases. True/False

P17

Answer 5

True

Question 5

What is a log-normal distribution?

P17

Answer 5

A log-normal distribution is a probability distribution of a random variable whose logarithm is normally distributed. This type of distribution is often used to model real-world variables that are positive and have a right-skewed distribution.

If the data is positively skewed, one common choice is the log-normal distribution, which is typically characterized by three parameters: a shape (s or σ), a scale (m or median) and a shift parameter (θ).

Question 6

At the extreme, if there are no negative outliers and the only positive outliers in the data, you might consider the exponential function. True/False

P18

Answer 6

True

Question 7

The Kolgomorov-Smirnov test can be used to see if the data fits a ____, ____, ____, ____ or ____ distribution. Improved versions of the tests include the Shapiro-Wilk and Anderson-Darling tests.

When testing for normality a p − value > 0.05 one can assume ____.

A straight forward test is the χ2 test. This is
however more used to test ____ distributions.

P18

Answer 7

normal
log-normal
Weibull
exponential
logistic
normality
non-normal

Question 8

What do probability plots do?

P18

Answer 8

Probability plots show the likelihood of a distribution fit.