Step 1 :Let's denote the full height of a certain species of tree as \(X\). We are given that \(X\) follows a normal distribution with a mean (\(\mu\)) of 118.2 ft and a standard deviation (\(\sigma\)) of 32.1 ft.
Step 2 :We are asked to find the probability that the height of a randomly selected tree is between 34.7 ft and 89.3 ft. Since the distribution is normal, we can use the z-score formula to standardize these values and then use the standard normal distribution to find the probability.
Step 3 :The z-score formula is: \(z = \frac{X - \mu}{\sigma}\), where \(X\) is the value we're interested in, \(\mu\) is the mean, and \(\sigma\) is the standard deviation.
Step 4 :First, we calculate the z-scores for 34.7 ft and 89.3 ft. For 34.7 ft, the z-score (\(z1\)) is \(-2.601\), and for 89.3 ft, the z-score (\(z2\)) is \(-0.900\).
Step 5 :Next, we find the area under the standard normal curve between these two z-scores. This area represents the probability we're looking for. The probability is approximately 0.179.
Step 6 :Final Answer: The probability that the height of a randomly selected tree is between 34.7 ft and 89.3 ft is approximately \(\boxed{0.179}\).