In order to estimate the mean amount of time computer users spend on the internet each month, how many computer users must be surveyed in order to be 95​% confident that your sample mean is within 11 minutes of the population​ mean? Assume that the standard deviation of the population of monthly time spent on the internet is 197 min. What is a major obstacle to getting a good estimate of the population​ mean? Use technology to find the estimated minimum required sample size.

((1.645*197)/11)^2

To estimate the minimum required sample size to be 95% confident that the sample mean is within 11 minutes of the population mean, we can use the formula:

n = [(Z * σ) / E]^2

Where:
n = required sample size
Z = Z-score corresponding to the desired confidence level (in this case, 95%, which corresponds to a Z-score of approximately 1.96)
σ = standard deviation of the population (given as 197 minutes)
E = margin of error (11 minutes)

Plugging in the values, we get:

n = [(1.96 * 197) / 11]^2

Using a calculator or spreadsheet software, we can compute the above expression to find the required sample size.

The major obstacle to getting a good estimate of the population mean in this scenario is sampling bias. It is essential to ensure that the sample is representative of the population of computer users. If the sample is biased (e.g., only includes heavy internet users or specific demographics), it may not accurately reflect the overall population, leading to skewed estimates. Proper sampling techniques, such as random sampling, can help reduce this bias and improve the estimate.