Consider the perimeter of a part in Example 5-32. Let X₁ and X₂ denote the length and width of a part with standard deviations 0.1 and 0.2 centimeters, respectively. Suppose that the covariance between X₁ and X₂ is 0.02. Determine the variance of the perimeter Y = 2X₁ + 2X₂ of a part. Compare and comment on the result here and in the example.