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
