We assume that our wages will increase as we gain experience andbecome more valuable to our employers. Wages also increase becauseof inflation. By examining a sample of employees at a given pointin time, we can look at part of the picture. How does length ofservice (LOS) relate to wages? The data here (data493.dat) is theLOS in months and wages for 60 women who work in Indiana banks.Wages are yearly total income divided by the number of weeksworked. We have multiplied wages by a constant for reasons ofconfidentiality.

(a) Plot wages versus LOS. Consider the relationship and whetheror not linear regression might be appropriate. (Do this on paper.Your instructor may ask you to turn in this graph.)

(b) Find the least-squares line. Summarize the significance testfor the slope. What do you conclude?

Wages =	+  LOS
t =
P =

(c) State carefully what the slope tells you about the relationshipbetween wages and length of service.

This answer has not been graded yet.

(d) Give a 95% confidence interval for the slope.(  ,  )

worker wages  los   size1    44.4711 150   Large2    45.2146 21   Small3    74.8957 123   Small4    72.0558 80   Small5    39.0496 83   Large6    47.9774 73   Small7    51.2293 86   Large8    69.0781 179   Large9    39.2668 39   Large10   53.424 125   Small11   51.8895 50   Large12   42.1108 67   Small13   50.9806 86   Small14   41.6564 26   Large15   64.8102 138   Large16   38.3316 30   Large17   70.1092 31   Large18   59.5725 22   Small19   72.6489 97   Large20   48.6928 129   Large21   65.3321 34   Large22   46.696 56   Small23   42.9948 100   Large24   63.7128 106   Small25   54.0511 170   Large26   37.2906 56   Small27   58.9101 44   Small28   80.6583 206   Large29   82.063 63   Large30   68.5583 114   Large31   48.3471 97   Small32   43.8155 109   Large33   58.983 16   Large34   37.3826 23   Small35   68.8845 63   Large36   55.8785 167   Large37   60.7873 46   Large38   43.4198 16   Small39   47.1446 77   Large40   44.8549 121   Small41   65.4524 29   Small42   45.9087 72   Small43   46.2893 28   Large44   65.7419 114   Small45   44.6151 37   Large46   89.5987 173   Small47   50.201 25   Large48   79.3444 55   Large49   44.7124 62   Small50   41.2526 63   Large51   67.4239 138   Large52   80.865 51   Large53   50.7154 86   Large54   40.1463 165   Small55   56.4553 29   Small56   49.2739 82   Large57   58.4318 17   Small58   58.0383 127   Large59   52.917 71   Small60   62.8699 28   Large