Suppose that you have obtained data by taking a random sample from a population and that you intend to find a confidence interval for the population mean, μ.Which confidence level, 95% or 99%, will result in the confidence interval giving a more accurate estimate of μ?

Which type of confidence interval should you use in this situation? A sample of 25 different payroll departments found that the employees worked an average of 310.3 days a year with a standard deviation of 23.8 days. The distribution is approximately normally distributed. Find the 90% confidence interval for the average days worked of all payroll departments.   Question 2 options:   1)  a confidence interval for the mean using a table value from the standard normal distribution.   2)  a confidence interval for the mean using a table value from the t distribution.   3)  a confidence interval for a proportion using a table value from the standard normal distribution.   4)  a confidence interval for proportion using a table value from the t distribution.   5)  none of the above.

The 95% confidence interval of the variance of a population is computed as (12.367,21.761). Interpret this confidence interval.

Imagine that a researcher wants to compare the intelligence levels of Poodles to all dogs.  He hypothesizes that Poodles will score differently than other dogs.  He uses a standard test of dog intelligence in his study. The population of all dogs has a mean of μ = 100, and an SD of 15.  He obtains a random sample of 500 Poodles and he finds that the mean intelligence score of the sample is 117.   Is this a one- or two- tailed test? Write the Ho and Ha for this research question. What kind of statistic should be calculated to test the hypothesis? Compute that statistic by hand What should the researcher conclude? Write a blurb describing the results

Given the following information: My confidence intervals: 90% confidence interval = (2.33, 2.56), and 99% confidence interval = (2.26, 2.63) My peer's confidence intervals: 90% confidence interval at ( 2.37 , 2.61 ) and 99% confidence interval  at ( 2.31 , 2.67). How do their confidence intervals compare with yours? If the population standard deviation is unknown and the sample size is not sufficiently large, would you still use the Normal distribution to calculate these confidence intervals, or would you choose another distribution? If the latter, which distribution would you choose?

Can you help me with this question from my Business Statistics class?