Basics of ML & AL Week 2 Challenge

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

ans - picture attached

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

ans - Generally simple mean varies with each sample . expected value comes into picture in non-uniform distribution. simple mean is calculated sum of all samples / number of samples . expected value we are given with probability of each event to occur, thus we have to consider prabability for each event then we get expected value.in the above example probability for each event is given so we calculated expected value that is 1.4 sum of probabilites should be one always. For example If the occurences are given for the event the simple mean is sufficient but if probability is given expected value should be considered.

3.Having skewness in the curve considered to be bad in the analysis

ans - No, skewness doesnot mean that is bad to analysis. skewness depends on the data. skewness is good or bad depend on the application of data .

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

ans -

5.Explain the curve on the right side

ans- from the right side of graph from the figure given in question

The data points ranges from -2 to +2 is 95.5%

explanation - from Z table for Z = 2 is 0.977 and for Z = -2 is 0.022

(97.77 - 2.2) = 95.5%

The data points ranges from -1 to +1 is 68.2%

explanation - From Z table for Z= 1 is 0.84134 and for Z = -1 is 0.15866

(84.13 - 15.86) = 68.27%