<span>The leading coefficient equals 8. A quadratic is written as a*x^2 + b*x + c, where a is the leading coefficient; here a = 8. Therefore the third statement is correct.</span>
Details provided:
Confidence level = 90%
Mean = 71 beats per minute
Standard deviation = 6 beats per minute
The formula for margin of error is z * δ / √n.
Where δ represents the population standard deviation and n is the sample size; z denotes the corresponding z-value.
For a 90% confidence level, the z-value is 1.645.
Thus, the margin of error is calculated as 1.645 * (6/√80) = 1.645 * (6/8.94) = 1.645 * 0.671 = 1.104.
