In: Statistics and Probability
The Accountability ratings for sixteen (16) school districts in the Delta Region of Mississippi on a 500 point rating scale are as follows: 102, 225, 222, 379, 208, 120, 250, 449, 229, 182, 214, 141, 150, 309, 256, & 263 Determine the following: a. Third Decile b. Fourth Decile c. Fifth Decile d. Sixth Decile e. Seventh Decile f. Eighth Decile g. Ninth Decile
Solution:
Arranging Observations in the ascending order, We get :
102,120,141,150,182,208,214,222,225,229,250,256,263,309,379,449
Here, n=16
a ) D3=(3(n+1)10)th value of the
observation
=(3⋅17 /10)th value of the observation
=(5.1)th value of the observation
=5th observation +0.1[6th-5th]
=182+0.1[208-182]
=182+0.1(26)
=182+2.6
=184.6
D3= 184.6
b ) D4=(4(n+1)10)th value of the
observation
=(4⋅1710)th value of the observation
=(6.8)th value of the observation
=6th observation
+0.8[7th-6th]
=208+0.8[214-208]
=208+0.8(6)
=208+4.8
=212.8
D4= 212.8
c ) D5=(5(n+1)10)th value of the
observation
=(5⋅17/10)th value of the observation
=(8.5)th value of the observation
=8th observation
+0.5[9th-8th]
=222+0.5[225-222]
=222+0.5(3)
=222+1.5
=223.5
D5= 223.5
d ) D6=(6(n+1)10)th value of the
observation
=(6⋅17/10)th value of the observation
=(10.2)th value of the observation
=10th observation
+0.2[11th-10th]
=229+0.2[250-229]
=229+0.2(21)
=229+4.2
=233.2
D6= 233.2
e ) D7=(7(n+1)10)th value of the
observation
=(7⋅17/10)th value of the observation
=(11.9)th value of the observation
=11th observation
+0.9[12th-11th]
=250+0.9[256-250]
=250+0.9(6)
=250+5.4
=255.4
D7=255.4
f ) D8=(8(n+1)10)th value of the
observation
=(8⋅17/10)th value of the observation
=(13.6)th value of the observation
=13th observation
+0.6[14th-13th]
=263+0.6[309-263]
=263+0.6(46)
=263+27.6
=290.6
D8= 290.6
g ) D9=(9(n+1)10)th value of the
observation
=(9⋅17/10)th value of the observation
=(15.3)th value of the observation
=15th observation
+0.3[16th-15th]
=379+0.3[449-379]
=379+0.3(70)
=379+21
=400
D9= 400