You have been asked to draw 600 cases from a population of 12,000. you decide on a systematic random sampling strategy. the sampling interval is:

To conduct a systematic random sampling out of the population, one should follow the following steps:
1. Create a list and assign numbers on every element in the population
       - Say a we assign cases 1 to 12,000

2. Decide the sample desired sample size
       - In our case, the sample size required is 600 cases

3. Select sampling interval
       - Simply divide the population with the sample size
       - 12,000/600 =20
       - Therefore, our sampling interval is 20. Meaning on every 20th element on the population we get to draw our pick until the desired sample size is accomplished.

The answer is b i think