Basics of ML & AL Week 2 Challenge

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

For the 1 question images has been attached below

2.What is the significance of expected value when simple mean (Sum of all observations/number of observations) is already in place
The mean is calculated for the uniform probability distribution and when the distribution is not uniform we have to calvulate the weighted average i.e. Expected value.

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

Skewness in the curve is neither good nor bad we can't determine, It depends upon for which buisness you are working.

4.Evaluate the probabilities for continuous normal distribution with given mean = 680 and standard deviation = 31
mean = 680
standard deviation = 31
First we have to find z score
z = (x-mean)/standard deviation
a) P(X<711)
(711-680)/31
31/31
=1
P(X<711) = 0.84

b) P(x>740)
(740-680)/31
60/31
=1.93
P(x>740) = 0.25

c) P(600<X<720)
(600-680)/31
-80/31
=-2.58
(720-680)/31
40/31
=1.29
P(600<X<720) = 0.78

d) P(X=720)
(720-680)/31
40/31
=1.29
P(X=720) = 0

5.Explain the curve on the right side
The curve shows standard normal distribution with
a) 68.2% within the 1 standard deviation
b) 95.4% within the 2 standard deviation