Please help The following output (from MINITAB) is for the least-squares fit of
ID: 3224264 • Letter: P
Question
Please help The following output (from MINITAB) is for the least-squares fit of the model ln y = beta_0 + beta_1 ln x + epsilon, when represents the monthly production of a gas well and x represents the volume of fracture fluid pumped in. (A scatterp of these data is presented in Figure 7.22.) a. What is the equation of the least-squares line for predicting ln y from ln x? b. Predict the production of a well into which 2500 gal/ft of fluid have been pumped. c. Predict the production of a well into which 1600 gal/ft of fluid have been pumped. d. Find a 95% prediction interval for the production of a well into which 1600 gal/ft of fluid have been pump.
Explanation / Answer
Part-a
Equation of the least-square line for predicting ln y from lnx is
Ln PROD=-0.444+0.708 LN FLUID
Or ln Y= -0.444+0.798 LN X
Part-b
We have Fluid=2500
So, Ln PROD=-0.444+0.708 LN(2500)= 5.0954
Hence Production of well= exp(5.0954)= 163.27
Part-C
We have Fluid=1600
So, Ln PROD=-0.444+0.708 LN(1600)= 4.7795
Hence Production of well= exp(4.7795)= 119.04
Part-d
From output we have
95% prediction interval for ln PROD when ln FLUID=ln1600=7.3778 is (3.9738, 6.9176)
So, 95% prediction interval for PRODUCTION= (exp(3.9738), exp(6.9176)) =(53.19 1009.89)