Please check attached vertical number line.
(a) The temperature differences are listed below:
Between Cities Temperature difference
Smithton and
Hedgeburough 2.5 - (-1.1) = 2.5 + 1.1 = 3.6
Hedgeburough and
East Bunting - 1.1 - (- 0.5) = - 1.1 + 0.5 = -0.6
East Bunting and
Smithton 2.5 - (- 0.5) = 2.5 + 0.5 = 3