Answer:
|Z| = 2.237 < 2.32 at 0.02 level of significance
Null hypothesis is accepted
Recommended that pregnant women not over eighteen years old get 85 milligrams of vitamin C each day
Step-by-step explanation:
Step(i):-
Given sample size 'n' = 45
Mean of the Population 'μ' = 85
Mean of the sample 'x⁻' = 81
Standard deviation of the sample 'σ' = 12 milligrams
Null Hypothesis: H₀:μ=85
Alternative Hypothesis: H₁:μ≠ 85
Step(ii):-
Test statistic
[tex]Z = \frac{x^{-} -mean}{\frac{S.D}{\sqrt{n} } }[/tex]
[tex]Z = \frac{81 -85}{\frac{12}{\sqrt{45} } }[/tex]
Z = -2.237
Level of significance = 0.02
Z₀.₀₂ = 2.32
|Z| = 2.237 < 2.32 at 0.02 level of significance
Conclusion:-
Null hypothesis is accepted
Recommended that pregnant women not over eighteen years old get 85 milligrams of vitamin C each day