For this assignment you are to imagine that you are part of a select marketing group. This select group has been asked to consider the Colorado City Convention and Visitors Bureau survey of 25 hotels in the local area. The survey is concerned with the current availability of rooms. The availability of the rooms was as follows:
90, 72, 75, 60, 75, 72, 84, 72, 88, 74, 105, 115, 68, 74, 80, 64, 414, 82, 48, 58, 60, 80, 48, 58, and 108.
Consider the average available. Identify the point estimate of the average number of available hotel rooms in this lesson from each sample. Construct and Interpret a 95% confidence level for the true mean number of available hotel rooms, based on the point estimate of each sample. Describe how the confidence intervals will change depending on whether the population standard deviation is known or unknown.
Find the mean first = sum of scores/number of scores
Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.
Standard deviation (SD) = square root of variance
95% = mean ± 1.96 SEm
SEm = SD/√n
I'll let you do the calculations.
From the equations above, you cannot estimate the confidence levels, if the SD is unknown.