The following table is similar to the table that appears in Example 12.4. The "What You Know" information has been provided. Complete the table by filling in the "How You Know It" column. What You Know How You Know It =X The sampling distribution of x is centered at the actual (but unknown) value of the population mean. = 1.3 29 1.3 An estimate of the standard deviation of x, which describes how the x values spread out around the population mean , is 0.24. 30 29 1.3 30 1.3 29 x 1.3