Arrange the marks on a stem-and-leaf plot in ascending order, list possible integer values for p given −4 < p ≤ 3, and solve 27p < 15p + 108.

Here are the solutions to the questions:

1. a. i. Arrange the marks on a stem-and-leaf plot in ascending order.
The masses are: 68, 42, 63, 57, 66, 54, 72, 58, 57, 73, 61, 40, 54, 63, 45, 63, 57, 63, 58, 56, 48, 39.
First, sort the data in ascending order:
38, 39, 40, 42, 45, 48, 54, 54, 56, 57, 57, 57, 58, 58, 61, 63, 63, 63, 63, 66, 68, 72, 73.

Stem-and-leaf plot:

$$\begin{array}{c|l} \text{Stem} & \text{Leaf} \\ \hline 3 & 8, 9 \\ 4 & 0, 2, 5, 8 \\ 5 & 4, 4, 6, 7, 7, 7, 8, 8 \\ 6 & 1, 3, 3, 3, 3, 6, 8 \\ 7 & 2, 3 \end{array}$$

Key: $3 | 8$ represents 38 kg.

1. a. ii. a. List all the possible values of p.
Given that $p$ is an integer such that $-4 < p \leq 3$.
The integers greater than $-4$ are $-3, -2, -1, 0, 1, 2, 3, \dots$.
The integers less than or equal to 3 are $\dots, 0, 1, 2, 3$.
Combining these conditions, the possible integer values for $p$ are:

$$\boxed{-3, -2, -1, 0, 1, 2, 3}$$

1. a. ii. b. Solve the inequality $27p < 15p + 108$ and illustrate the truth set on a number line.