7. Mrs. Paulson is constructing a 90% confidence interval for the difference of means based on independent simple random samples from two populations. The sample sizes are n, = 6 and n, =14. She draws dotplots
of the sample data to check one of the conditions for using two-sample i procedures. Which of the following
descriptions of those dotplots would suggest that it is safe to perform inference?
(a) Both dotplots are roughly symmetric. There are no outliers in either dotplot.
(b) Both dotplots are roughly symmetric. The dotplot of sample 2 has an outlier.
(c) Both dotplots are strongly skewed to the right. There are no outliers in either dotplot.
(d) Both dotplots are roughly symmetric. Both dotplots have one upper outlier
(e) i procedures are not recommended in any of these cases.