Answer:
78.88%
Step-by-step explanation:
We have been given that

The z-score formula is given by

For 

For 

Now, we find the corresponding probability from the standard z score table.
For the z score -1.25, we have the probability 0.1056
For the z score 1.25, we have the probability 0.8944
Therefore, the percent of the trees that are between 20 and 30 years old is given by
0.8944 - 0.1056
= 0.7888
=78.88%
The first thing we must do for this case is to define a variable.
We have then:
x: weight of each pallet with cement
We then have the following equation:
16x = 4856
Clearing x we have:
x = (4856) / (16)
x = 303.5 punds
Answer:
each pallet with cement weigh:
x = 303.5 punds