Answer: 615.44units
Step-by-step explanation:
Given:
The speed, s, is measured in miles per hour, and distance, y, is measured in yards.
The regression line is given by
...(i)
To find:
The slope and y-intercept of the regression line.
Solution:
The general form of linear regression line is
...(ii)
where x is variable. In the given equation the variable is denoted by s.
On comparing (i) and (ii), we get

It means slope is 52.45 and y-intercept is 4.17.
The slope, b = 52.45, indicates that the distance increases by 52.45 yards for every one mile per hour of speed.
The y-intercept, a = 4.17, is the distance estimated by this model if the speed is zero miles per hour.
Therefore, the correct option is A.
Answer: (b) The focus of an ellipse is always located precisely at the center of the ellipse.
Step-by-step explanation:
An ellipse is defined as <em>"a closed curve with two axes of symmetry (major axis and minor axis) that results in cutting the surface of a cone by an oblique plane to the axis of symmetry with an angle greater than that of the generatrix with respect to the axis of revolution"</em>. That is why the ellipse is considered a conic figure.
To understand it better: an ellipse has two points on its major axis that are equidistant from the center , which are called foci, being this distance constant. In addition, the eccentricity allows to know how far the foci are from the center of the ellipse.
Therefore, the statement that indicates an ellipse has only one focus located precisely at the center is incorrect.