Consider a data set with five observations f(Yi; Xi); i = 1;2; : : : ;5g, where X1 = −4, X2 = −2, X3 = 0, X4 = 2, and X5 = 4. We fit a SLR model (i. e., Yi = β0 + β1Xi + i) to this data set, where the i’s are independent. Suppose you are told that var(i) / exp(Xi)σ2 for i = 1;2; : : : ;5. Based on the available information, find appropriate weights w1; w2; : : : ; w5 for the weighted least squares, and discuss how this choice remedies nonconstant variance in the SLR model.

Adecibel is a logarithmic unit that can be used to measure the intensity of a sound. the function y = 10logx gives the intensity of a sound in decibels, where x is the ratio of the intensity of the sound to a reference intensity. the reference intensity is generally set at the threshold of hearing. use the graphing utility to graph the decibel function.a whisper has a sound intensity of 30 decibels. use your graph to you complete the following statement. the sound intensity of a whisper is times the reference intensity.