Working Hypothesis Report Assignment Example | Topics and Well Written Essays - 250 words

Working Hypothesis Report - Assignment Example Listed below is the interest rate charged on a a) Based on the dataset, we conclude that the Mean of the sample is 48.18. Accepting the given population Mean of 50 and the standard deviation of 3, this sample is within .01 or is included within the 99% range of probability. b) Using a z-statistic is applicable due to the range of data that fall evenly above and below a given mean on a normal distribution. The z-statistic tests to see if the sample follows the expectation of the population. In this case, the sample complies with the population parameters, as the mean falls within 1.918 standard deviations of the population mean. A z-test is appropriate, because the population variance is known. If we did not have this information, then a t-test would be more appropriate. Given the fact that the sample contained an outlier of 55.8, one would expect that the sample is skewed based on that data point. This is true, because if we were to remove the outlier, the new sample mean would be 47.33 and the corresponding z-stat would be -2.67, giving a p-value of 0.0076. This result would lead us to accept Ha, since p-value Variance: This is the average of the sum of squares of the variation from the mean. In English, this means that you take the difference between each data item and subtract the mean. You then square each number. Total them together and divide by the number of data points minus the number of variables. You will see this as ∑(x-u)2 / (n-1) Data point is the average for your sample data, while mean is the population mean and std deviation is the std deviation for the population. You will normally be given these numbers for the population, so you are comparing your