Ahmed found the volume of a cone having both a height and a diameter of 6 centimeters. His work is shown below. Step 1 Find the
radius. radius = StartFraction 6 Over 2 EndFraction = 3 centimeters Step 2 Find the area of the base. Area of base = Pi (3) squared = 9 pi centimeters squared Step 3 Multiply the area of the base by the height. 9 pi times 6 = 54 centimeters cubed Step 4 Divide 54 by 3 to find the volume of the cone. Volume of the cone = StartFraction 54 Over 3 EndFraction = 18 centimeters cubed What was Ahmed’s first error? In Step 1, the radius should be found by multiplying the diameter by 2. In Step 2, the formula 2 pi r should be used to find the area of the circle. In Step 3, the resulting area should be in terms of pi. In Step 4, the units of the resulting volume should be Centimeters squared.
The samples he chose may not be a representative sample because the number of students per foreign language class may not be the same. One class may have a very large number of students while another may have only a few. Taking equal number of students per class is not a representative sample.<span />
