Question

1. Use the following information for the next two problems. Police in a particular city want to check drivers for up-to-date vehicle registration and proof of insurance. It is not possible nor practical for them to stop every vehicle on their streets. Instead, they create a road block and stop every 10th automobile. During one weekend they stop 900 automobiles, of which 27 don’t have valid registration and 45 don’t have proof of insurance.

   Which one of the following gives the population and the sample?

   	a.	Population: All automobiles on the city’s streets Sample: The 900 automobiles stopped
   	b.	Population: All automobiles on the city’s streets Sample: The 45 automobiles without proof of insurance
   	c.	Population: All police officers in the city Sample: The 900 automobiles stopped
   	d.	Population: The 900 automobiles stopped Sample: The 27 automobiles not having valid registration

5 points   

2. Which one of the following gives the name of the sampling design described in the story?

	a.	Voluntary response sample
	b.	Systematic random sample
	c.	Simple random sample
	d.	Stratified random sample

Answer 1

Here out of all the automobiles 900 are stopped

So sample is 900 automobiles stoppped

Hence answer here is

a.	Population: All automobiles on the city’s streets Sample: The 900 automobiles stopped

In systematic sample we start with a random starting point and then select sample with a fixed, periodic interval

Here we start with 10th automobile and then each 10th are selected firn 900 samples

So answer is

b. Systematic random sample