Assume that the helium porosity (in percentage) of coal samples taken from any particular seam is normally distributed with true standard deviation 0.76.(a) compute a 99% ci for the true average porosity of a certain seam if the average porosity for 16 specimens from the seam was 4.85. (give answers accurate to 2 decimal places.)

Step-by-step explanation:

Formula to calculate the confidence interval for population mean is given by :-

, where = sample mean

n= sample size.

z*= Critical value

= Population standard deviation.

As per given , we have

n= 16

From z-table , the critical value for 99% confidence = z*=2.576

Now , 99% confidence interval for true average porosity of a certain seam will be :

Hence, the required  99% CI for the true average porosity of a certain seam =

-6 is the correct option from the above given options

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this