Question

Students taking an Introduction to Macroeconomics class reported the number of credit hours that they were taking in the current semester. Summary statistics are shown in the table below. For tuition the college charges $73 per credit hour plus a flat student fee of $34 per semester. For example, a student taking 12 credit hours would pay $34 + $73*(12) = $910 for that semester.

Summary Statistics for Credit Hours

	s	min	Q1	median	Q3	max
14.2	3.2	11	13.9	15.5	15.7	18

a) If a student's tuition for the semester is $1,628.59, what is the corresponding z-score?

b) What is the interquartile range (IQR) of the tuition paid by the students in the class?

Answer 1

Let x denales the numbes of credit hocesy. Y denate students tuition fee for the semester. then, YhX BYXXX Y = 34 + 73X Now E(Y) = 34 + 73 E(X) = 34+ 73x K4.2 = 1070.6 dollar. VTY)= t132 VIX =(73)2x (3-2)2 Syvy 233.6 dollar. dollar 54 568.96 hence, b Z-Score X- Elx) or y- Elw Jvlys Vruj Z-score 1688.59 - 107006 233.6 557699 2.388656 233.6 intesquartile range = 83-8, = (34+73 x 15•7) - (34 +23 X 13.9) 21180.1-1048.7 = 131.4 dollas geant) dan (x) 18,(x)) Median (X)/ 0₂(X)" maxlx) 5 11 13.9 15.5 1507 conose, 13.67 ta 14.2 18 3.2