Relative density was determined for one sample of second-growth Douglas fir 2 x 3 4s with a low percentage of juvenile wood and another sample with a moderate percentage of juvenile wood, resulting in the following data

Type n x s

Low 35 0.523 0.0543

Moderate 54 0.489 0.0450

Estimate the difference between true average density for the two types of wood.

0.03865

Step-by-step explanation:

Since the true density for the two types of trees are given, we would evaluate the average for both of them

Low percentage of juvenile wood density = 0.523 and 0.0543

Average density = 0.523 + 0.0543/2

Average density = 0.55015

Moderate percentage of juvenile wood density = 0.489 and 0.0450

Average density = 0.489 + 0.0450/2

Average density = 0.5115

Therefore, difference in true average density for the two woods are = 0.55015 - 0.51150

= 0.03865