Question

Does each of the following statements pertain to an estimate or an estimator? If the statement pertains to an estimate is it an interval estimate or point estimate? If the statement pertains to an estimator write the estimator. (i) The head of a publishing company says that the firm’s computer Science textbook will sell about 9000 copies in 2012. (ii) A census prefers the median to the mean as a measure of central tendency for the income distribution of families in a standard metropolitan city. (iii) A stock market analyst, who appears on the television programme, estimates that the price of a particular common stock will be between 50 and 60 at the end of six months."

Answer 1

Estimate is a numerical value, like the average/mean of given data samples.

Estimator is a rule or formula for the statistic.  This is the statistical variable that is represented by  x in statistics.

1)  The statement pertains to  an average number of books sold during that year 2012...  It is about estimate.. 9000 copies.
   here estimator = number of CS text book copiess that will be sold in a year.

2)  The statistic that the Census prefers is the median..  Here we are talking about the estimator.  Which formula or rule to choose for best representing the distribution of income.

3)  Here we are talking about the estimate.. the computed value of the expected price of stock.
      x = estimator = price of the common stock after 6 months