1. Calculate Population Kurtosis from the following data
`85,96,76,108,85,80,100,85,70,95`

Solution:
Kurtosis :
Mean `bar x=(sum x)/n`

`=(85+96+76+108+85+80+100+85+70+95)/10`

`=880/10`

`=88`

`x`	`(x - bar x)` `= (x - 88)`	`(x - bar x)^2` `= (x - 88)^2`	`(x - bar x)^3` `= (x - 88)^3`	`(x - bar x)^4` `= (x - 88)^4`
85	-3	9	-27	81
96	8	64	512	4096
76	-12	144	-1728	20736
108	20	400	8000	160000
85	-3	9	-27	81
80	-8	64	-512	4096
100	12	144	1728	20736
85	-3	9	-27	81
70	-18	324	-5832	104976
95	7	49	343	2401
---	---	---	---	---
880	0	1216	2430	317284

Population Standard deviation `sigma = sqrt((sum (x - bar x)^2)/n)`

`=sqrt(1216/10)`

`=sqrt(121.6)`

`=11.0272`

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Population Kurtosis `= (sum(x - bar x)^4)/(n*S^4)`

`=317284/(10*(11.0272)^4)`

`=317284/(10*14786.56)`

`=2.1458`

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2. Calculate Population Kurtosis from the following data
`10,50,30,20,10,20,70,30`

Solution:
Kurtosis :
Mean `bar x=(sum x)/n`

`=(10+50+30+20+10+20+70+30)/8`

`=240/8`

`=30`

`x`	`(x - bar x)` `= (x - 30)`	`(x - bar x)^2` `= (x - 30)^2`	`(x - bar x)^3` `= (x - 30)^3`	`(x - bar x)^4` `= (x - 30)^4`
10	-20	400	-8000	160000
50	20	400	8000	160000
30	0	0	0	0
20	-10	100	-1000	10000
10	-20	400	-8000	160000
20	-10	100	-1000	10000
70	40	1600	64000	2560000
30	0	0	0	0
---	---	---	---	---
240	0	3000	54000	3060000

Population Standard deviation `sigma = sqrt((sum (x - bar x)^2)/n)`

`=sqrt(3000/8)`

`=sqrt(375)`

`=19.3649`

---

Population Kurtosis `= (sum(x - bar x)^4)/(n*S^4)`

`=3060000/(8*(19.3649)^4)`

`=3060000/(8*140625)`

`=2.72`

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3. Calculate Population Kurtosis from the following data
`73,70,71,73,68,67,69,72,76,71`

Solution:
Kurtosis :
Mean `bar x=(sum x)/n`

`=(73+70+71+73+68+67+69+72+76+71)/10`

`=710/10`

`=71`

`x`	`(x - bar x)` `= (x - 71)`	`(x - bar x)^2` `= (x - 71)^2`	`(x - bar x)^3` `= (x - 71)^3`	`(x - bar x)^4` `= (x - 71)^4`
73	2	4	8	16
70	-1	1	-1	1
71	0	0	0	0
73	2	4	8	16
68	-3	9	-27	81
67	-4	16	-64	256
69	-2	4	-8	16
72	1	1	1	1
76	5	25	125	625
71	0	0	0	0
---	---	---	---	---
710	0	64	42	1012

Population Standard deviation `sigma = sqrt((sum (x - bar x)^2)/n)`

`=sqrt(64/10)`

`=sqrt(6.4)`

`=2.5298`

---

Population Kurtosis `= (sum(x - bar x)^4)/(n*S^4)`

`=1012/(10*(2.5298)^4)`

`=1012/(10*40.96)`

`=2.4707`

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