Answer:
95% confidence interval for the true average triglyceride level of people in West Palm Beach
(215.519 , 224.480)
Step-by-step explanation:
Step(l) :-
Given a blood test on 30 randomly selected people was conducted and yielded a mean triglyceride level of 220, with a standard deviation of 12.
Given sample size n = 30
mean of the sample x⁻ = 220
standard deviation of the sample = 12
Step(ll):-
95% of confidence intervals:-
95% confidence interval for the true average triglyceride level of people in West Palm Beach
[tex](x^{-} - t_{0.95} \frac{S}{\sqrt{n} } , x^{-} + t_{0.95} \frac{S}{\sqrt{n} } )[/tex]
[tex](220 - t_{0.95} \frac{12}{\sqrt{30} } , 220+ t_{0.95} \frac{12}{\sqrt{30} } )[/tex]
The degrees of freedom ν = n-1 = 30-1 =29
t₀.₉₅ = 2.0452
[tex](220 - 2.0452 \frac{12}{\sqrt{30} } , 220+ 2.0452 \frac{12}{\sqrt{30} } )[/tex]
(220 - 4.4808 , 220 + 4.4808)
(215.519 , 224.480)
Conclusion:-
95% confidence interval for the true average triglyceride level of people in West Palm Beach
(215.519 , 224.480)