Final answer:
The standard error of the mean (SEM) is calculated as 'c) 20/√64', which results in an SEM of 2.5 for the given sample of adults' cholesterol levels.The correct option is C.
Step-by-step explanation:
The question asks to find the standard error of the mean (SEM), which is calculated as the sample standard deviation (s) divided by the square root of the sample size (n). Given a sample standard deviation of 20 and a sample size of 64 adults, the SEM is 20/√64, which corresponds to the option c) 20/√64.
To calculate it:
- Take the square root of the sample size: √64 = 8.
- Divide the sample standard deviation by this number: 20 / 8 = 2.5.
Therefore, the standard error of the mean in this scenario is 2.5.