The following data are the calories per half-cup serving for 16 popular chocolate ice cream brands reviewed by Consumer Reports (July 1999): 270 150 170 140 160 160 160 290 190 190 160 170 150 110 180 170 Is it reasonable to use the t confidence interval to compute a confidence interval for m, the true mean calories per half-cup serving of chocolate ice cream? Explain why or why not.

The Coefficient of Variation: C.V. = S / x(bar) X(bar) Mean of data Examples: #1 X(bar) 54 ft S 26 ft C.V. = S / x(bar) = 26/54 = .48 or 48% #2 X(bar) 2 hours S 2.7 hours C.V. = 2.7 / 2 = 1.35 NOTICE: the units cancel when you divide the two numbers, therefore the answer does not have units!! Chebyster’s Theorem: For any set of numbers with mean x(bar) and standard deviation, S, atleast (1 – (1/ k^2) x 100%) of those numbers must fall between [x(bar) – kS] and [x(bar) + kS] ________________________________________________________________________ Quartiles: specific values that attempt to divide quantitative data into four equal parts. 1. find median 2. take median of lower half and upper half 3. then you will find the three medians, th