1. Stem-and-Leaf Diagram: Compute the median, interquartile range (IQR), and identify any outliers from the stem-and-leaf diagram of ages, and plot a box plot.
2. Normal Distribution: Calculate probabilities for normally distributed packages, including the probability that a randomly selected package weighs less than 10 kg, and the weight of the lightest 15% of packages moved by Jemima.
3. Regression Line: Interpret the regression line in terms of the relationship between performance scores and salaries, including predicting new values and verifying reliability.
4. Normal Distribution with Changing Parameters: Solve for probabilities related to changes in mean and standard deviation of normal distributions, and find the probability that at least one of several randomly selected values is negative.