Statistics · Module 1
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Compare these references after your own attempt. You can read them at any time; they do not record a live model or vendor run.
Statistics · Module 1
Compare these references after your own attempt. You can read them at any time; they do not record a live model or vendor run.
1A. The 340-row count answers “How many joined tracking-event rows are present?” assuming each joined row is one event. The fraction of shipments late requires one late status per shipment and a denominator of 100 evaluable shipments. Repeated events from one shipment neither create new shipments nor provide independent copies of the outcome.
1B. Three of six evaluable shipments are late: 50%. “Three of six shipments with known timing were late; two of eight had unknown timing.” If both unknowns are on time, the all-eight rate is 3/8=37.5%; if both are late, it is 5/8=62.5%. These are possible-value bounds, not a sampling interval.
1C. One defensible contract: describe recorded reliability among 240 shipments in fictional weeks 1–8, unit=shipment, outcome=actual_minutes > promised_minutes, comparing standard with priority. Report group counts and route mix. Service choice is observational, so the difference does not isolate a causal service effect. Actual time alone ignores different promises.