1)The S.D of weight of some members is 4.5 k.g.
After some time it was observed that each member was under weight by 0.5 kg then what is new S.D?
a) < 4.5 b) > 4.5 c) = 4.5 d) None
2)Two unbiased dies are thrown then the excepted value of sum on the sides of the die
a) 3.5 b) 7 c) 6 d) 12
As regards the first question, I think S.D. will not change if every item was erroneously entered with same amount of difference. Only a measure of central tendency will change (i.e., mean, median, etc.) and the measure of dispersion will not change. Hence, according to me the answer is (c), viz., 4.5 kg.
| Outcome | Possible Ways | Probability | Expected Value | ||
| 2 | 1 | '1/36 | '2/36 | ||
| 3 | 2 | '2/36 | '6/36 | ||
| 4 | 3 | '3/36 | '12/36 | ||
| 5 | 4 | '4/36 | '20/36 | ||
| 6 | 5 | '5/36 | '30/36 | ||
| 7 | 6 | '6/36 | '42/36 | ||
| 8 | 5 | '5/36 | '40/36 | ||
| 9 | 4 | '4/36 | '36/36 | ||
| 10 | 3 | '3/36 | '30/36 | ||
| 11 | 2 | '2/36 | '22/36 | ||
| 12 | 1 | '1/36 | '12/36 | ||
| Expected Value | 7 |
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