On the basis of extensive tests, the yield point of a particular type of mild steel-reinforcing bar is known to be normally dist
ributed with σ = 100. the composition of the bar has been slightly modified, but the modification is not believed to have affected either the normality or the value of σ.
1) The formula used for determining the confidence interval is Sample mean +/- Critical value (or z-score corresponding to 90% confidence) * Standard error of mean 8439 +/- 1.645 * 100/sqrt 25 8439 +/- 1.645 * 20 8439 +/- 32.9 2) The only difference in this case is finding the critical value i.e., z-score corresponding to 92% confidence which is 1.75 approximately Then the confidence interval is 8439 +/- 1.75 * 100/sqrt 25 8439 +/- 1.75 * 20 8439 +/- 35 Lower limit is 8439 - 35 = 8404 The upper limit is 8439 + 35 = 8474
The best and most correct answer among the choices provided by the question is the third choice.
The notation "<span>AB (with line over) =4" is the equation that has the most correct notation.</span> I hope my answer has come to your help. God bless and have a nice day ahead!
