Describing difference in variances

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Q1) Sample of 25 concession stand purchases at October 22 matinee of Bride of Chucky showed a mean purchase of $5.29 with standard deviation of $3.02. For October 26 evening showing of the same movie, for sample of 25 purchases mean was $5.12 with standard deviation of $2.14. Means appear to be very close, but not variances. At α = .05, is there a difference in variances? Illustrate all steps clearly, including illustration of the decision rule.

Q2) In bumper test, 3 types of autos were deliberately crashed into barrier at 5 mph, and resulting damage (in dollars) was estimated. 5 test vehicles of each type were crashed, with the results shown below.

Research question: Are mean crash damages the same for these three vehicles? 

Crash Damage ($)

Goliath

Varmint

Weasel  

1,600

1,290

1,090  

760

1,400

2,100  

880

1,390

1,830  

1,950

1,850

1,250  

1,220

950

1,920  

Reference no: EM1319154

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