- AAbout one tyre in twelve in the store is likely to be worn past the limit, though the exact number among the 540 unchecked tyres cannot be fixed from this check
- BExactly 50 of the 600 tyres in the store are worn past the limit
- CNone of the 540 tyres that were not checked is worn past the limit
- DThe check supports nothing at all about the 540 tyres that were not checked
Step-by-Step Solution
Five in sixty is one in twelve, and because every tyre had the same chance of being picked the 60 stand in for the store as a whole, so the finding may be carried across as an estimate. It remains an estimate: 'exactly 50' claims a precision the check cannot deliver, and 'none of the 540' is contradicted by the very worn tyres that turned up. The last option throws away the one thing a properly drawn sample is good for.
Answer: A) About one tyre in twelve in the store is likely to be worn past the limit, though the exact number among the 540 unchecked tyres cannot be fixed from this check