Question

a student wants to determine if a local parks soil is healthy and tests 10 soil samples from various playgrounds. is this a valid and random sample? (1 point)
yes, because the samples come from different locations in the park
no, because the samples only come from playground areas
yes, because 10 samples are enough to draw conclusions
no, because the samples should come from a variety of areas around the town.

Explanation:

A valid random sample should represent the entire population (the local park's soil). If samples are only from playground areas, they don't represent the whole park. 10 samples might be enough if they're from diverse park areas, but here they're limited. The town - wide area is irrelevant as the study is about the local park.

Answer:

No, because the samples only come from playground areas.