Question

Many ancient tombs were cut from limestone rock that contained uranium. Since most such tombs are not​ well-ventilated, they may contain radon gas. In one​ study, the radon levels in a sample of 12 tombs in a particular region were measured in becquerels per cubic meter (Bq/m3). For this​ data, assume that x(over-bar)= 3,469 Bq/m3 and s= 1,135 Bq/m3. Use this information to​ estimate, with 95% confidence, the mean level of radon exposure in tombs in the region. Interpret the resulting interval.

Answer 1

Answer:

95% confidence interval of the mean level of random exposure in tombs in the region.

(2746.868 , 4191.132)

Step-by-step explanation:

Step(i):-

Given sample size 'n'= 12

Mean of the sample  x⁻ = 3,469

and standard deviation of the sample 's' = 1,135

95% confidence intervals are determined by

$(x^{-} - t_{0.05} \frac{S}{\sqrt{n} } , x^{-} +t_{0.05} \frac{S}{\sqrt{n} } )$

Degrees of freedom = n-1 = 12-1= 11

Step(ii):-

95% confidence intervals are determined by

$(3469- 2.201 \frac{1135}{\sqrt{12} } , 3469+2.201\frac{1135}{\sqrt{12} } )$

(  3469-722.132 , 3469 +722.132)

(2746.868 , 4191.132)