Basics of Probability and Statistics Week 1 Challenge

Ans no 1 :-This has to do with a concept called Degrees of freedom . It basically means the number of variables that are free to vary.This same idea is applied in case of sample variance, since we use n data values & mean, degrees of freedom is becomes n - 1 instead of n.Population variance refers to the value of variance that is calculated from population data, and sample variance is the variance calculated from sample data.

Ans no 2:- Cluster sampling is a type of sampling method in which we split a population into clusters, then randomly select some of the clusters and include all members from those clusters in the sample.Stratified sampling is a type of sampling method in which we split a population into groups, then randomly select some members from each group to be in the sample

Ans No 3:-The size of the sample to be taken is equal to the size of the population. This means that the number of different random samples that can be taken is 1

Ans No 4:-If there are 2 Jacks in a pile of 52 cards already, and you add two more Jacks, then your probablilty of drawing out a Jack is 4 out of 54 (or 4/54) you get 2/26.

Ans No 5:- the probability of getting same number on both the dice is 1/6.

Ans No 6 :-Standard deviation measures how far apart numbers are in a data set. Variance, on the other hand, gives an actual value to how much the numbers in a data set vary from the mean. Standard deviation is the square root of the variance and is expressed in the same units as the data set. It is a measure of spread of data about the mean. SD is the square root of sum of squared deviation from the mean divided by the number of observations. This formula is a definitional one and for calculations, an easier formula is used.

Ans no 2 schreenshort