25 periodicals have a mean of $180 and a standard deviation of $12. form a 95% confidence interval on the population mean.
95% confidence interval is the mean ± 2 standard error of the mean (SE).
SE = SD/√n
√ = square root
You can do the calculations. I hope this helps. Thanks for asking.
Just to note your typo.
To form a 95% confidence interval on the population mean, we will use the formula:
Confidence Interval = mean ± (critical value * standard deviation / sqrt(n))
Where:
- mean is the sample mean
- critical value is the z-score corresponding to the desired confidence level (95% in this case)
- standard deviation is the sample standard deviation
- n is the sample size
In your question, the mean of the periodicals is given as $180, and the standard deviation is $12. However, the sample size (n) is not mentioned. The sample size is vital for calculating the confidence interval. Please provide the sample size (number of periodicals) to proceed with the calculation.