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 (data197.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.


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

worker wages  los   size1    55.2228 62   Large2    72.6471 43   Small3    64.7938 28   Small4    83.1899 52   Small5    74.6722 77   Large6    45.3301 156   Small7    43.6869 16   Large8    54.4083 253   Large9    41.5534 134   Large10   43.4756 79   Small11   64.5044 105   Large12   51.4939 172   Small13   46.8273 39   Small14   61.5737 59   Large15   40.4888 192   Large16   42.5272 77   Large17   44.0275 98   Large18   49.1887 45   Small19   41.9127 110   Large20   44.5922 59   Large21   45.2959 41   Large22   67.5828 63   Small23   49.1524 119   Large24   49.6111 26   Small25   41.2403 62   Large26   64.3923 114   Small27   48.8709 73   Small28   53.2818 55   Large29   52.4652 26   Large30   38.5335 65   Large31   42.8304 56   Small32   62.9239 25   Large33   37.9765 42   Large34   60.7783 105   Small35   64.4702 78   Large36   63.7232 89   Large37   56.527 41   Large38   50.0613 188   Small39   40.3449 59   Large40   48.4422 37   Small41   72.214 55   Small42   44.3634 79   Small43   68.0063 81   Large44   52.1295 120   Small45   40.9163 72   Large46   54.7163 24   Small47   42.0233 35   Large48   115.9302    24   Large49   39.8092 127   Small50   40.779 40   Large51   37.6496 65   Large52   49.833 121   Large53   53.0945 143   Large54   76.8681 34   Small55   53.227 24   Small56   44.4872 136   Large57   59.3171 111   Small58   59.3403 79   Large59   44.9148 19   Small60   45.3378 72   Large