Suppose you are trying to find the average age of trees in the National Forest in Florida. A lifelong Forest resident claims that the average age of trees is 20 years, but you believe it is older than that. In order to test this, you take a sample of 10 trees. The computed value of the sample average is 24.5 years. The underlying distribution of tree ages is assumed to be normal and the standard deviation of tree ages is known to be 3 years of age based on historical data.

Perform this test at the alpha = 0.01 level. Compute the test statistic for this test.

Note: Round to the nearest thousandth.

ANSWER IS 4.743

please explain step by step