OpenCyber Academy
Rapid course · Lesson 6 · English
Course code: OCA-009Lesson 06: OCA-009-A006

62.5 percent is not eight of eight

Open, free learning for anyone who wants to protect people and technology. No account is required to read this text or its worked answers.

Lesson map

Lesson 06. Map, example, EX052.

flowchart TD
  A["Five met checks out of eight"] --> B["Script prints 62.5 percent"]
  B --> C{"May the percent erase a gap line?"}
  C -->|No| D["Keep the percent and every gap"]
  C -->|Yes| E["That erasure is not this run"]

Equal weights in the script are not equal weights in the decision.

Logical drawing

arithmetic
    100 times 5 divided by 8 prints 62.5
decision
    one missing privileged control outweighs the percent
print
    the percent stays
    the three gap lines stay

Learning outcomes

After this chapter, you should be able to:

  1. Explain where 62.5 percent comes from.
  2. Say why that percent can mislead.
  3. Refuse a note that drops a gap line to reach eight of eight.

6.1 The percent counts rows. It does not rank them.

The script counts met rows, divides by eight, and multiplies by one hundred, showing one decimal place. Five met rows therefore print as 62.5 percent. Every row has the same weight inside that division. Elena's reading does not. Chapter 4 says all three gaps concern control over the system's rules, and that one missing control over privileged changes matters more than several minor items. A reader who keeps only 62.5 percent can describe a mostly finished setup. A reader who also keeps the gap lines sees that the unmet rows are the privileged ones: the timelock, the vendor-access review, and the monitoring of role changes and pauses. Dropping a gap line would be a different print. This file does not contain that print. The five met rows stay met, including the daily reconciliation, the backup restore, and the written incident list. Their passes do not fill the three gaps, and the percent does not either.

6.2 Worked example

Quote the percent only together with the rows it counted.

Lesson table; scroll horizontally to read all columns →

Claim What the arithmetic supports Decision
"Five of eight rows are met, printed as 62.5 percent." The embedded division May stay
"The three gap lines are still under that percent." The same run May stay
"62.5 percent means the privileged gaps are minor." The opposite of chapter 4 Refuse
"Round it to eight of eight." A different numerator Refuse

Synthetic case. The percent belongs to this synthetic checklist. It is not a measure of the cafés' takings.

Errors and limits

A single percent hides which row failed. Here the failed rows are the ones that govern the rules.

Apply

Worked answers

EX052. No. 62.5 percent stays. It is not 8 of 8. One missing privileged control still outweighs the percentage.