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Fuel Efficiency Testing

GMAT-RYLTMY

Document 1: Fuel Efficiency Data from Consumer Watchdog Group

Document 2: Consumer Watchdog Group’s Major Concern

Document 3: Statistical Testing on Mean and Median

Consider each of the following statements. Does the information in the three sources support the inference as stated?

Yes

No

Yes

No

Half of all vehicles had fuel efficiency greater than the sample mean.

Yes

No

In general, S will have a greater value than R for data, like this set, in which there are a small number of vehicles with much higher fuel efficiency than the others.

Yes

No

If you take the vehicle with the highest fuel efficiency out of this data set, S decreases by more than 5%.

Yes

No

The high S statistic (based on all 12 vehicles) gives serious reason to be concerned that the manufacturer’s stated fuel efficiency of 29 mpg may be incorrect.