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 (data426.dat) (seebelow) is the LOS in months and wages for 60 women who work inIndiana banks. Wages are yearly total income divided by the numberof weeks worked. We have multiplied wages by a constant for reasonsof confidentiality.

(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 therelationship between wages and length of service. This answer hasnot been graded yet.

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

(______ , _______)

worker wages  los   size1    55.0977 28   Large2    60.3942 54   Small3    55.5375 35   Small4    48.6244 27   Small5    56.5636 188   Large6    38.237 156   Small7    43.5632 30   Large8    42.7156 61   Large9    39.143 65   Large10   46.1205 23   Small11   49.5348 68   Large12   63.0939 76   Small13   37.3613 57   Small14   86.4907 44   Large15   62.1521 103   Large16   49.2244 51   Large17   61.2332 63   Large18   38.775 14   Small19   47.1923 127   Large20   38.5997 39   Large21   38.8533 105   Large22   46.0433 164   Small23   64.581 70   Large24   41.4075 17   Small25   55.9129 143   Large26   47.352 107   Small27   43.1829 22   Small28   51.886 197   Large29   51.3497 46   Large30   60.591 40   Large31   55.6434 77   Small32   37.9994 34   Large33   50.3993 85   Large34   39.2409 88   Small35   51.1068 118   Large36   44.8436 58   Large37   39.4066 78   Large38   64.675 47   Small39   59.4471 142   Large40   70.2038 93   Small41   47.4302 168   Small42   44.8665 33   Small43   39.4258 27   Large44   71.8007 69   Small45   38.5246 46   Large46   71.9274 68   Small47   51.5816 22   Large48   65.4135 18   Large49   64.9034 76   Small50   73.0817 97   Large51   45.4468 35   Large52   44.2239 56   Large53   68.4574 87   Large54   37.7713 60   Small55   46.0706 86   Small56   45.3591 62   Large57   53.7606 21   Small58   104.9657    74   Large59   40.4731 71   Small60   60.6301 97   Large