Paper aircraft flight distances to capture a population mean

The backside of El Niño has brought strong gusty winds across Pohnpei. With the wind both a headwind and crosswind, coming in from the east-northest, the aircraft severely underperformed the expected population mean. In both classes the pre-class point estimate for the population mean of 581 cm was not within the 95% confidence interval. As a statistics class experiment, the results are more "useful" if the population mean is captured by the sample, but the reality is that the population mean is based on more typical becalmed weather.
Clarisa Marie and Casan-Jenae, 8:00 section

As I have done in the past, the planes were thrown from the balcony.

Distances were measured perpendicular to the building using a fiberglass 30 meter tape measure. This replaced an 8 meter tape measure used in the past. The longer tape measure did speed up the distance measurements.
Upstairs with the SMART board running

Paper aircraft flight distance data was added to a Google Docs Sheets spreadsheet. 

Being Pi Day, the class started with a Pi Day video

Sepe Swinfred Salik and Celine Salud Yoma, 9:00 section

Board work

The headwind/crosswind combination produced record low 384 cm and 358 cm average flight distances. These would pull down the population mean, but not sufficiently for a 95% confidence interval to capture the population mean. Across all terms 80% of the 95% confidence intervals captured the current population mean of 564 cm. If the confidence level is increased to 99%, then 95% of the samples produce a 95% confidence interval that captures the current population mean.

This should not be puzzling: conditions are varying term to term. The changing conditions effectively change the population to which the population mean belongs. The high coefficient of variation in this particular experiment allows me to "get away" with capturing the population mean as often as I do.

Headwinds are more common in spring, thus perhaps separating out fall and spring might produce better results.


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