[hoist_failure] Revise fault-tree lecture and add exercises

[jstac]

Revisions by @thomassargent30 to hoist_failure:

• treats the three lognormal components as i.i.d.; reframes the direct vs FFT convolution timing
• compares computed percentiles with Table 11 of Greenfield and Sargent (1993) and the DOE 1990 point estimate; new "Reading the answer" section
• converts exercise-start/end blocks to exercise and adds further exercises

No new bib entries.

Split out of tom_mfg (commit 8bf3b2c) so each lecture can be reviewed separately. Content is unchanged from Tom's commit; only the relevant quant-econ.bib entries and _toc.yml lines are included here.

Merge order: independent — can be merged at any time, in any order relative to the other split PRs (#1067, #1068, #1069, #1070/#1071). Each PR adds its bib entries at a different place in quant-econ.bib, so they do not conflict.

🤖 Generated with Claude Code

[jstac]

TODO before merge: check this lecture against the QuantEcon style guide (writing, code, math, figures, references, doc links, admonitions).

[github-actions]

📖 Netlify Preview Ready!

Preview URL: https://pr-1067--sunny-cactus-210e3e.netlify.app

Commit: 32910ad

📚 Changed Lectures

• hoist_failure

---

Build Info

• Workflow: Build Project [using jupyter-book]

[mmcky]

@jstac Style guide check done ✅ Nice set of new exercises!

The lecture was already in good shape ({cite:t}, ipython3 cells, a captioned new figure, default_rng, qe.Timer), so I've pushed one small commit (32910ad) with the remaining fixes:

• Timing claims in prose: the style guide prefers qualitative wording to hard-coded speeds, so "slower by more than two orders of magnitude" now reads "far slower still". In the hoist_ex4 solution I dropped "far quicker … a couple of seconds", since the comparison actually runs the other way (~2 s for the 13 convolutions vs ~0.2 s for 10⁶ draws on my laptop). The point about reproducibility stays.
• One sentence per paragraph in the hoist_ex1 solution.
• Italic for emphasis, bold for definitions: stops, spacing, far tail, overall precision.
• Notation: \Pr(…) → \mathbb{P}\{…\} (3 places) and "i.i.d." → "IID".
• Sentence case for the "fast Fourier transform" heading and its mid-sentence use.

Nothing changes the substance. Happy to adjust anything.

[jstac]

Thanks @mmcky @thomassargent30 . Merging.

[mmcky]

✅ Translation sync completed (zh-cn)

Target repo: QuantEcon/lecture-python.zh-cn
Translation PR: QuantEcon/lecture-python.zh-cn#285
Files synced (1):

• lectures/hoist_failure.md