STM2EPS : Heat-Generating Capacity - Heat-Generating Capacity Assignment Writing Help

Internal Code : 1AAJIC

Heat-Generating Capacity Assignment Writing Help

TASK A company wishes to compare the heat-generating capacity of coal from two different mines. To do so, they randomly sample 25 pieces of coal from the first mine and 95 from the second. The mean heat-generating capacity for the coal sampled from first mine is 7,340 millions of calories per ton and the associated standard deviation is 2,110. From the second mine, the mean and standard deviation are 8,670 and 4,200 respectively. Let ?1 and ?2 denote the true mean heat-generating capacity for the first and second mine respectively. For the two-sample t-test, the degrees of freedom (df) is approximately df = 78 and you should use this value in what follows. (a) What is the estimated mean difference (i.e. estimate of ?1 ? ?2) between the mean heat-generating capacities? ( (b) Calculate the standard error for this estimated mean difference. (c) Calculate a 95% confidence interval for the difference in two means. You may use the fact that t78,0.975 = 1.991. (d) Using your confidence interval from above, do you think that there is evidence that one mine produces coal with higher heat-generating capacity? Explain clearly.