STATISTICAL TECHNIQUES AND TOOLS
SAMPLING DISTRIBUTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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the statistic is calculated from a random sample.
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in many samples, the values of the statistic are very close to the value of the parameter.
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in a single sample, the value of the statistic is equal to the value of the parameter
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in many samples, the values of the statistic are centered at the value of the parameter.
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Detailed explanation-1: -Normal. The correct option is (d) in many samples, the values of the statistic are centered at the value of the parameter.
Detailed explanation-2: -A statistic is said to be an unbiased estimator of a parameter if the mean of all its possible values equals the parameter; otherwise, it is said to be a biased estimator. An unbiased estimator yields, on average, the correct value of the parameter, whereas a biased estimator does not.
Detailed explanation-3: -An unbiased estimator of a population parameter is an estimator whose expected value is equal to that parameter. An unbiased estimator is said to be consistent if difference between estimator and the parameter grows smaller as sample size grows larger.
Detailed explanation-4: -In order for an estimator to be unbiased, its expected value must exactly equal the value of the population parameter. The bias of an estimator is the difference between the expected value of the estimator and the actual parameter value. Thus, if this difference is non-zero, then the estimator has bias.