The confusion matrix tells the truth faster — step 7 of 7
Checkpoint
One last thing before we move on. Same surface as a write step — but the lesson doesn't complete until this passes.
Checkpoint. Build the confusion matrix for one week of refund decisions, then print a plain-English summary line so a non-technical teammate can read it.
Write summarize(cases) that counts tp/fp/tn/fn (fraud = positive)
and returns the string:
caught {tp} fraud, missed {fn}, false alarms {fp}
Print the result. Expected output:
caught 2 fraud, missed 2, false alarms 1