Challenge

Basics of Probability and Statistics Week 1 Challenge

YYamini Chillari10 Aug 2022

1..... Why there is a difference in the formula of variance for population and sample

Population variance refers to the value of variance that is calculated from population data, and sample variance is the variance calculated from sample data. Due to this value of denominator in the formula for variance in case of sample data is 'n-1', and it is 'n' for population data.

2.....Difference between stratified and clustered sampling

In Cluster Sampling, the sampling is done on a population of clusters therefore, cluster/group is considered a sampling unit. In Stratified Sampling, elements within each stratum are sampled. In Cluster Sampling, only selected clusters are sampled. In Stratified Sampling, from each stratum, a random sample is selected

3........How many different samples can be created out of population of size n

Lets assume Population Size = N

and sample size = n

so the total number of samples created is = NCn

4......What is the probability of drawing 2 jacks from a pack of card

Total number of cards are 52 , and jacks are 4

So, total outcomes = 52 favorable, outcomes = 2

So, the probability of getting 2 jacks

= Favorable outcomes / Total outcomes = 2 / 52 = 1/13

5.......What is the probability that both the numbers on dice are same while rolling 2 dice

[ (1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)

(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)

(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)

(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)

(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)

(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6) ]

So, pairs with same numbers are (1,1) (2,2) (3,3) (4,4) (5,5) (6,6) i.e. total 6 pairs

Total outcomes = 36

Favorable outcomes = 6

Probability of getting pair with same numbers = Favorable outcomes / Total outcomes = 6 / 36 = 1/6

So, P(N, N) = 1/6.

6.......Why standard deviation when variance can measure the dispersion in data

variance is square of sigma ,so it will change the units of quantities

standard deviation is square root of variance i.e..sigma

so, using standard deviaton we get our original units to compute

Basics of Probability and Statistics Week 1 Challenge

Ship work like this
in your own course.

Talk to a career counsellor

Ship work like thisin your own course.

Talk to a career counsellor

Ship work like this
in your own course.