Question

Download the data set “Cigarette Contents” in your preferred technology format (StatCrunch, Excel). Column 1 denotes the amount of tar per cigarette (milligrams) in king-sized cigarettes that are nonfiltered. Column 4 denotes the amount of tar per cigarette (milligrams) in menthol cigarettes that are filtered.

Using technology (StatCrunch, or Excel) compute a 95% confidence interval for the mean amount of tar in each cigarette group and paste the screen printouts obtained from the technology. Post an image of your technology output Describe in words what each confidence intervals represents.  

Compare the confidence intervals obtained for the filtered and nonfiltered cigarettes. Based on your confidence intervals, do you see evidence that the filtered cigarettes are healthier? Explain.

https://1drv.ms/x/s!ArV35t3Ew2wCjAef4BgC_OoQQPMr

Basically i need these results for king tar and menth tar.

Answer 1

The 95% CI for king tar and menth tar is found using EXCEL. Screenshot below.

KING TAR MENTH TAR Mean Standard Error Median Mode Standard Deviation Sample Variance Kurtosis Skewness Range Minimum Maximum Sum Count Confidence Level(95.0%) 12.92 0.745922248 13 13 3.72961124 13.91 2.114706963 1.209849504 17 21.12 Mean 0.646322933 Standard Error 20 Median 20 Mode 3.231614663 Standard Deviation 10.44333333 Sample Variance 5.464695568 Kurtosi -1.163853581 Skewness 17 Range 10 Minimum 27 Maximum 19 323 25 1.539507844 528 Sum 25 Count 1.333944962 Confidence Level(95.0%) 95% CI 19.78605504 95% CI 11.38049216 22.45394496 14.45950784

The CI is found as $\textup{mean } \pm \textup{confidence level}$

The 95% confidence interval for the mean amount of tar in king tar is ${\color{Blue} \left ( 19.786,22.454 \right )}$

We are 95% sure that the tar content in king tar cigarette is between 19.786 and 22.454.

The 95% confidence interval for the mean amount of tar in menth tar is ${\color{Blue} \left ( 11.38,14.46\right )}$

We are 95% sure that the tar content in meth tar cigarette is between 11.38 and 14.46.

Clearly the CI $\left ( 11.38,14.46\right )< \left ( 19.786,22.454 \right )$

The conclusion is the tar content of menth tar is significantly less than that of king tar.