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%
Answer: 3
Step-by-step explanation:
7-3+4-2+9=15
15/5=3
Answer:
A=2(wl+hl+hw)=2·(8·12+4·12+4·8)=352
Step-by-step explanation:
brainliest?
Answer:
a) 
b) 
Step-by-step explanation:
Given that:
population mean
= 30,000
sample size n = 800
population proportion p = 0.6
a)
The mean of the the sampling distribution is equal to the population proportion.


b)
The standard deviation of the sampling distribution can be estimated by using the formula:





