# The gypsy moth is a serious threat to oak and aspen trees

The gypsy moth is a serious threat to oak and aspen trees. A state agriculture department places traps throughout the state to detect the moths. When traps are checked periodically, the mean number of moths per trap is only 1.3, but some traps have several moths. The distribution of moth counts is strongly right skewed, with standard deviation 1.4. A random sample of 60 traps has x = 0.9 and s = 2.1.

Let X = the number of moths per trap

(a) For the population distribution, what is the …
…mean?
…standard deviation?

(b) For the distribution of the sample data, what is the …
…mean?
…standard deviation?

(c) What shape does the distribution of the sample data probably have?
Left skewed
Right skewed
Exactly Normal
Approximately Normal

(d) For the sampling distribution of the sample mean with n = 60, what is the …
…mean?
…standard deviation?

(e) What is the shape of the sampling distribution of the sample mean?
Approximately Normal
Exactly Normal
Left skewed
Right skewed