Jacki is conducting a study that examines the effects of multi-vitamins on common cold symptoms. She hopes to generalize her findings to the school-age population of children in a specified region in her state. She knows the population of children is 9,000. She is going to do a survey study and decides to sample 7000 children. Regarding Jacki's sample we know that
A) it is substantially too small.
B) it is not representative.
C) it will result in large sampling bias.
D) it is substantially too big.

Question

Quizplus · Accepted Answer

The sample size of 7000 children is substantially too big for a population of 9000 children. The rule of thumb is that the sample size should be around 10% of the population size, which in this case would be 900. A sample size of 7000 may result in greater precision, but it is also likely to be much more expensive and time-consuming. Additionally, using such a large sample size may result in a loss of power if the sample is too heterogeneous.

Jacki Is Conducting a Study That Examines the Effects of Multi-Vitamins