Question

A random sample of 400 tins of Vanaspathi has mean weight 4.96 kg and S.D. 0.4 kg. Test at 1% L. O. S. that the average weight of tins of Vanaspathi is less than 5 kg.

Answer 1

Given : n = 400; x̄ = 4.96; S = 0.4, α = 1% µ = 5

H₀ : Mean weight of tens is 5 kg (H_o: p = 5kg) –

H₁ : Mean weight of tens is less than 5kg

(H₁ : µ < 5 kg) { Lower tail test; -K}

under H₀ the test statistic is :-

At α = 1% the lower tail critical value – K = -2.33

Here Z_cal lies in A.R .

∴ H₀ is Accepted

Conclusion: Mean weight of tins is 5kg.