
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Given that ${a_n}$ is an arithmetic sequence, and ${S_n}$ is the sum of its first $n$ terms, with $a_5=19$, and $S_5=55$, find the slope of the line that passes through points $P(3, a_3)$ and $Q(4, a_4)$.

Present the answer in LaTex format: \boxed{Your answer}
user