A quality inspector samples 30 bolts from a large shipment a

A quality inspector samples 30 bolts from a large shipment, and measures the length of each.

He finds

that 17 of them, or

57%,

meet a length specification.

He concludes

that exactly

57%

of the bolts in the shipment meet the specification.

The inspector\'s

supervisor concludes that the proportion of good bolts is likely to be close to

57%,

but not exactly equal to

57%.

Which conclusion

is appropriate?

The quality inspector\'s conclusion.

The supervisor\'s conclusion.

Solution

the supervisor\'s conclusion is appropriate because this conclusion is based on sample. therefore, the population proportion will be close to 57%.