160 heads and 240 tails resulted from 400 tosses of a coin. Find a 95% confidence interval for the probability of a head. Does this appear to be a fair coin?
| A. | Cannot be said to be fair |
| B. | Can be or cannot be said to be fair |
| C. | Can be said to be fair |
| D. | Yes with +1 |
Answer : A Explanation : Chance of getting head 1 or p = 1/2 Expected frequency = np = 400 x 1/2 = 200 Standard error = √npq = √1/2 x 1/2 x 400 = 10 Actual difference = 200 - 160 = 40. This difference is greater than three times of the standard error. Hence the coin cannot be said to fair. Hence the answer is (a). |
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Option: A Explanation : Explanation will come here. Explanation will come here. Explanation will come here. Explanation will come here. Explanation will come here. |
