Interim Progress Review Question 5 - Essay Example

normal distribution for the given sample, because the sample is a randomly distributed set of human reactions—which ideally fall in the pattern of the normal distribution. The 95% confidence interval is given by the formula where M is the mean, SE is the standard error of the distribution, and z is the z-score for the confidence interval being used. The standard score z is derived by subtracting the sample mean from an individual raw score and then dividing the difference by the sample standard deviation.

z represents the number of standard deviations between the raw score and the mean. (b) CNN and ActMedia provided a television channel that showed news feature and advertisements. It was targeted at people waiting in grocery checkout queues. The television programmes were designed with a 8 minute cycles on the assumption that the population mean time a customer stands in the queue is 8 minutes. A sample of 120 shoppers at a major grocery store produces a sample mean waiting time of 7.5 minutes with a sample standard deviation of 3.2 minutes. There is a close relationship between confidence intervals and significance tests.

Specifically, if a statistic is significantly different from 0 at the 0.05 level then the 95% confidence interval will not contain 0. All values in the confidence interval are plausible values for the parameter whereas values outside the interval are rejected as plausible values for the parameter. . There is a similar relationship between the 99% confidence interval and Significance at the 0.01 level. (Lane, Lu, Peres, Zitek) Adding and subtracting from the figure of 7.5 hours, only 5% of normally distributed queues will last longer than 7.5 + 0.57496 = 8.

07496 minutes. To be more precise, 95.46% of queues will fall within (7.5 - 0.57496) = minutes and 8.07496 minutes = 8 min 4.498 seconds. We can also go the p-value and t test way, using the "level of significance" method. Since we cannot obtain the p-values directly, we thought of