To determine the average height of trees in a national forest, 10 trees are randomly selected. Their heights in feet are 85.4,87.6,87.1,85.6,85.9,85.3,84.9,83.7,84.0,and 85.2. To ensure the accuracy of the data, another set of 10 trees is randomly selected. Their heights are 87.1,88.0,84.2,85.3,86.5,84.2,83.2,84.1,85.2,and 87.3. What is the difference between the mean heights of the trees of these two random samples? Express your answer as a decimal. Do not round your answer.(1 point)

____ feet

1 answer

To calculate the difference between the mean heights of the two samples of trees, we first need to find the mean height for each sample.

Sample 1 heights: 85.4, 87.6, 87.1, 85.6, 85.9, 85.3, 84.9, 83.7, 84.0, 85.2

Calculating the mean for Sample 1: \[ \text{Mean}_1 = \frac{85.4 + 87.6 + 87.1 + 85.6 + 85.9 + 85.3 + 84.9 + 83.7 + 84.0 + 85.2}{10} \] \[ = \frac{864.7}{10} = 86.47 \]

Sample 2 heights: 87.1, 88.0, 84.2, 85.3, 86.5, 84.2, 83.2, 84.1, 85.2, 87.3

Calculating the mean for Sample 2: \[ \text{Mean}_2 = \frac{87.1 + 88.0 + 84.2 + 85.3 + 86.5 + 84.2 + 83.2 + 84.1 + 85.2 + 87.3}{10} \] \[ = \frac{864.1}{10} = 86.41 \]

Finding the difference between the means of the two samples: \[ \text{Difference} = \text{Mean}_1 - \text{Mean}_2 = 86.47 - 86.41 = 0.06 \]

Thus, the difference between the mean heights of the trees in the two random samples is 0.06 feet.