Answer: A. An estimator is a function of a sample of data to be drawn randomly from a population whereas an estimate is the numerical value of the estimator when it is actually computed using data from a specific sample.
Step-by-step explanation: The estimator is simply used to on obtaining an estimate from a sample of data. Thus, the estimator may be described as a function built according to a set of defined rules and statistical component which is used to infer a numerical value of an estimate from a given sample of observed data. Hence, the estimator may be regarded as the function or rules adopted in our quest to obtain an estimate for a given population from a sample of data. The value obtained for the mean of a sample of data is called an estimate of the population, the rules for Deriving the estimated value is called the estimator.