Basics of ML & AL Week 2 Challenge

Q1)Calculate all 4 business moments using pen and paper for the below data set?

Q2)What is the significance of expected value when simple mean (Sum of all observations/number of observations) is already in place

ANS:Expected value is used when we want to calculate the mean of a probability distribution. This represents the average value we expect to occur before collecting any data. Mean is typically used when we want to calculate the average value of a given sample. This represents the average value of raw data that we’ve already collected.

Q3)Having skewness in the curve considered to be bad in the analysis?

ANS:

Skewness describes how much statistical data distribution is asymmetrical from the normal distribution, where distribution is equally divided on each side. If a distribution is not symmetrical or Normal, then it is skewed, i.e., it is either the frequency distribution skewed to the left side or to the right side.

So if we having a skewness in the curve considered , if there’s too much skewness in the data, then many statistical models don’t work effectively. the tail region may act as an outlier.

4)Evaluate the probabilities for continuous normal distribution with given mean = 680 and standard deviation = 31

a)P(X<711)

b)P(X>740)

c)P(600<x<720)

d)P(X=720)

ANS:

Q5)

ANS:

from the above normal distributionwe can say that

Aprroximately 68.3% of the values fall within 1 standard deviation of the mean

Approximately 95.5% of the values fall within 2 standard deviation of the mean

Approximately 97.7% of the values fall within 3 standard deviation of the mean