Considering the situation described, the scientist's null and alternative hypothesis are described by:
Null hypothesis 
; Alternative hypothesis 
.
<h3>What are the hypothesis tested?</h3>
At the null hypothesis, it is tested if there is no difference, that is, the difference of the means represented by 
is of 0, hence:
At the alternative hypothesis, it is tested if there is a difference, hence:
More can be learned about an hypothesis test at brainly.com/question/26454209
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%
If the question is how many students are girls, than it's ten(10).
Answer:
B
Step-by-Step Explanation:
if you do a <u>Percent Proportion</u> you will get:
_1__ = _0.1_ 0.1x10=1
1000 100
