Aviation and high-altitude physiology is a specialty in the study of medicine. Let x = partial pressure of oxygen in the alveoli (air cells in the lungs) when breathing naturally available air. Let y = partial pressure when breathing pure oxygen. The (x, y) data pairs correspond to elevations from 10,000 feet to 30,000 feet in 5000 foot intervals for a random sample of volunteers. Although the medical data were collected using airplanes, they apply equally well to Mt. Everest climbers (summit 29,028 feet).

x	6.9	4.7	4.2	3.3	2.1	(units: mm Hg/10)
y	44.8	32.3	26.2	16.2	13.9	(units: mm Hg/10)

(a) Verify that x = 21.2, y = 133.4, x² = 102.64, y² = 4192.42, xy = 653.62, and r 0.979.

x
y
x2
y2
xy
r

(b) Use a 10% level of significance to test the claim that > 0. (Use 2 decimal places.)

t
critical t

ConclusionReject the null hypothesis, there is sufficient evidence that > 0.Reject the null hypothesis, there is insufficient evidence that > 0. Fail to reject the null hypothesis, there is insufficient evidence that > 0.Fail to reject the null hypothesis, there is sufficient evidence that > 0. (c) Verify that S_e 2.9425, a -2.581, and b 6.901.

Se
a
b

(d) Find the predicted pressure when breathing pure oxygen if the pressure from breathing available air is x = 4.3. (Use 2 decimal places.) (e) Find a 95% confidence interval for y when x = 4.3. (Use 1 decimal place.)

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(f) Use a 10% level of significance to test the claim that > 0. (Use 2 decimal places.)

t
critical t

Conclusion

Reject the null hypothesis, there is sufficient evidence that > 0.

Reject the null hypothesis, there is insufficient evidence that > 0.

Fail to reject the null hypothesis, there is insufficient evidence that > 0.

Fail to reject the null hypothesis, there is sufficient evidence that > 0. (g) Find a 95% confidence interval for and interpret its meaning. (Use 2 decimal places.)

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Interpretation- pick one For a one-unit increase in oxygen pressure breathing only available air, the oxygen pressure breathing pure oxygen increases by an amount that falls outside the confidence interval.

For a one-unit increase in oxygen pressure breathing only available air, the oxygen pressure breathing pure oxygen decreases by an amount that falls within the confidence interval.

For a one-unit increase in oxygen pressure breathing only available air, the oxygen pressure breathing pure oxygen decreases by an amount that falls outside the confidence interval.

For a one-unit increase in oxygen pressure breathing only available air, the oxygen pressure breathing pure oxygen increases by an amount that falls within the confidence interval.