Refer to Problem 18.

a. Is the estimate of age based on 500 plots influenced by sampling error?

Why?

b. How would the sampling error of the estimate of mean age change if the investigators had used a sample of only 100 plots?

Data from problem 18

The average age of piñon pine trees in the coast ranges of California was investigated by placing 500 10-hectare plots randomly on a distribution map of the species using a computer. Researchers then found the location of each random plot in the field, and they measured the age of every piñon pine tree within each of the 10-hectare plots. The average age within the plot was used as the unit measurement. These unit measurements were then used to estimate the average age of California piñon pines.