Prediction of rank in LDC (Ernakulam) exam

Ever since my wife wrote the LDC (Lower Division Clerk) – Ernakulam district exam and was on tenterhooks regarding the rank, she was always scouring the net for possible position in the rank list. She got 64 marks and the probable list contained 2202 persons. So, I offered her a prediction, based on statistics. It was a very very long time that I’d got anything to do with statistics, so a thorough search on the Net had to be made. The calculation proceeded along the following lines.

Representative sample for proportions n₀ = Z².pq / e²  (Eqn 1)

Where 
n₀ = sample size, Z² = abscissae of normal curve that cuts off an area at the tails (1 – desired confidence level, taken as 95%), 
e = desired level of precision (taken as +/-5%), 
p = estimated proportion of an attribute that is present in the population (taken as 0.5 for maximum variability), 
q = 1-p.

Z = 1.96 for 95% confidence level (from normal curve)

Substituting the values in Eqn 1, n₀ = 385

Applying finite population correction, n = n₀ / (1 + (n₀ – 1)/N) (Eqn 2)

Where n = required sample size, n₀ = obtained in previous step and N = population (2202, for this case)

Substituting in Eqn 2, n = 327

The roll numbers of shortlisted candidates were exported to Excel and a macro was run to identify 327 random numbers from the list. Marks obtained by these numbers were collected from Kerala PSC’s website, tabulated in Excel and sorted. My wife’s marks were introduced in the middle of people who obtained exactly 64 marks each. She came at 41^st place.

This was for a sample size for 327, extrapolating to the total, 41 x 2202 / 327 = 276.

Applying precision of +/-5%, her rank can be anywhere between 165 to 385. This I say with 95% confidence, though I have a hunch that it will be between 250-300.

I’m writing this on Mar 15, 2012, the results are expected by this month-end. We’ll see then!

31.3.2012

The results have been published. Her rank came out to be 254.
Prediction is 100% successful. Statistics is great!

Seven Categories of Religious People

Richard Dawkins categorises people into seven categories, based on their religious beliefs and the probability which they assign to divine existence. This makes for curious reading and helps people understand what is meant by agnosticism.

1. Strong theist: 100% probability of God. In the words of C G Jung, 'I do not believe, I know'.

2. Very high probability but short of 100%. De facto theist. 'I cannot know for certain, but I strongly believe in God and live my life on the assumption that he is there'.

3. Higher than 50% but not very high. Technically agnostic but leaning towards theism. 'I am very uncertain, but I am inclined to believe in God'

4. Exactly 50%. Completely impartial agnostic. 'God's existence and non-existence are exactly equiprobable'.

5. Lower than 50% but not very low. Technically agnostic, but leaning towards atheism. 'I don't know whether God exists, but I'm inclined to be sceptical'.

6. Very low probability, but short of zero. De facto atheist. 'I cannot know for certain, but I think God is very improbable, and I live my life on the assumption that he is not there'.

7. Strong atheist. 'I know there is no God, with the same conviction as Jung "knows" there is one'.

Source: The God Delusion by R. Dawkins

Book-banning Indian Democracy

Freedom of expression is an inalienable right of a citizen living in a democracy. India eminently guarantees this freedom to its citizens in its constitution under article 19(1)(a) which reads "All citizens shall have the right to freedom of speech and expression". Before the ink drying on these letters, there comes a proviso in article 19(2), stating "Nothing in sub-clause (a) of clause (1) shall affect the operation of any existing law, or prevent the State from making any law, in so far as such law imposes reasonable restrictions on the exercise of the right conferred by the said sub-clause in the interests of the sovereignty and integrity of India, the security of the State, friendly relations with foreign States, public order, decency or morality, or in relation to contempt of court, defamation or incitement to an offence". No one objects to preventing such expressions which threatens the soverignty, security, foreign relations and integrity of the country, contempt of court, incitement to violence and offending decency or morality. But public order? That is a sweeping generalization which in effect nullifies the spirit of the freedom granted. This is a loophole any government can adopt to stifle dissent. In a country which is swamped with fanatics and religious minorities whose passions are offended by even innocuous cartoons, no wonder the ruling faction chose this subclause to summarily ban books which they don't approve of. Below is a list of books banned in India at present. (Source: The Hindu, dt. Mar 4, 2012).


1. Hindu Heaven - Max Wylie (1934)
2. The Face of Mother India - Katherine Mayo (1936)
3. Old Soldier Sahib - Frank Richards (1936)
4. The Land of the Lingam - Arthur Miles (1937)
5. Mysterious India - Moki Singh (1940)
6. The Scented Garden (Anthropology of the sex life in the Levant) - Bernhard Stern (1945)
7. What has Religion done for Mankind - Watchtower Bible and Tract Society (1955)
8. Rama Retold - Aubrey Menen (1955)
9. Dark Urge - Robert W Taylor (1955)
10. The Ramayana - Aubrey Menen (1956)
11. Captive Kashmir - Aziz Beg (1958)
12. The Heart of India - Alexander Campbell (1959)
13. The Lotus and the Robot - Arthur Koestler (1960)
14. Nine Hours to Rama - Stanley Wolpert (1962)
15. Unarmed Victory - Bertrand Russell (1963)
16. Nepal - Tony Hagen (1963)
17. Ayesha - Kurt Frishchler (1963)
18. Lady Chatterley's Lover - D H Lawrence (1964)
19. The Jewel in the Lotus (A Historical Survey of the Sexual Culture of the East) - Allen Edwards (1968)
20. The Evolution of the British Empire and Commonwealth from the American Revolution - Alfred Le Ray Burt (1969)
21. A Struggle between Two Lines over the Question of How to Deal with U.S. Imperialism - Fan Asid-Chu (1969)
22. Man from Moscow - Greville Wynne (1970)
23. Early Islam - Desmond Steward (1975)
24. Nehru: A Political Biography - Michael Edwards (1975)
25. India Independent - Charles Bettelheim (1976)
26. China's Foreign Relations since 1949 - Alan Lawrence (1978)
27. Who Killed Gandhi - Lourenco de Sadvandor (1979)
28. Understanding Islam through Hadis - Ram Swarup (1982)
29. Smash and Grab: Annexation of Sikkim - Sunanda Datta-Ray (1984)
30. The Satanic Verses - Salman Rushdie (1988)
31. Soft Target: How the Indian Intelligence Service Penetrated Canada - Zuhair Kashmeri and Brian McAndrew (1989)
32. The Polyester Prince - Hamish McDonald (1998)
33. The True Furqan - Al Saffee and Al Mahdee (1999)
34. Islam: A Concept of Political World Invasion - R V Bhasin (2007 - Maharashtra)
35. Great Soul: Mahatma Gandhi and His Struggle with India - Joseph Lelyveld (2011 - Gujarat)


Even Bertrand Russell couldn't escape the censoring of some obscure chicken-headed bureaucrats!