Question

solved examples on comparison of two sets of observations statistics diploma​

Answer 1

Answer:

For group-1: ∑xi / 10 = 2 ⇒ ∑xi = 20

∑xi2 / 10 – (22) = 2

∑xi2 = 60

For group-2 : ∑yi / n = 3

∑yi = 3n

∑yi2 / n – 32 = 1

∑yi2 = 10n

Now, combined variance

2 = [∑(xi2 + yi2) / (10 + n)] – [∑ (xi + yi) / (10 + n)]2

(17 / 9) = [60 + 10n] / [10 + n] – [20 + 3n]2 / [10 + n]2

17 (n2 + 20n + 100) = 9 (n2 + 40n + 200)

8n2 – 20n – 100 = 0

2n2 – 5n – 25 = 0

n = 5