During a Test Period, an Experimental Group of 10 Vehicles

question 8

Multiple Choice

During a test period, an experimental group of 10 vehicles using an 85 percent ethanol-gasoline mixture showed mean CO₂ emissions of 667 pounds per 1000 miles, with a standard deviation of 20 pounds. A control group of 14 vehicles using regular gasoline showed mean CO₂ emissions of 679 pounds per 1000 miles with a standard deviation of 15 pounds. At α = 0.05, in a left-tailed test, the critical value to compare the means (assuming equal variances) is:

• A)-2.508
• B)-2.074
• C)-1.321
• D)-1.717

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Definitions:

Percentage

A percentage is a way of expressing a number as a fraction of 100, used to describe proportions and changes in quantities.

Value

The worth or importance of something, often determined by its utility, scarcity, or demand.

HST

Harmonized Sales Tax, a combined tax that includes both federal and provincial sales taxes, applied in some regions of Canada.

Pay-No-HST

A situation or offer where the Harmonized Sales Tax (HST) is not applied, making the purchase effectively tax-free.