According to the problem we start with 6000 gal of E10 which means there is 10% of ethanol in this 6000, with ths information we can calculate the amount of ethanol already in the mixture:
The relationship between ethanol and total fluid can be represented like this:
Based on this relationship we can build the one that we are looking for:
the total solution will be:
where X is the E5 solution volume
and the TotalEthanol would be:
where E5ethanol (5% Ethanol 95% Gasoline) would be:
Now replacing in the relationship we found before:
Solving for X:
We should mix 1500 gal of E5 to make an E9 mixture
Using sampling concepts, it is found that the sampled is biased because only parents who attend the school's musical show are surveyed, hence they are not very likely to support the decrease, and the population proportion should be greater than the one found in the show.
<h3>How are samples classified?</h3>
Samples may be classified as:
- Convenient: Drawn from a conveniently available pool.
- Random: All the options into a hat and drawn some of them.
- Systematic: Every kth element is taken.
- Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.
- Stratified: Also divides the population into groups. Then, a equal proportion of each group is surveyed.
A sample has to take into account all aspects of the population, otherwise it is biased. In this problem, either people support the decrease, or they do not. Only people that went to the show were surveyed, that is, people who are unlikely to support the decrease, which generates bias, as the population proportion should be greater than the one found in the show.
More can be learned about sampling concepts at brainly.com/question/25122507
The x value will change to y avlue and vice versa
so x---> y and y---> x
(x,y) --> (y,x)
B
Answer:
The first four.
Step-by-step explanation:
There are 3 main postulates. SSS, SAS, and AAS. This simply refers to how we prove a triangle congruent. With SSS, all 3 sides must be congruent (either proven or given). AAS is when you have 2 angles congruent with a side next to one of the angles. NOT IN BETWEEN (there's an image as to what I'm talking about below). Finally, SAS. This is when you have a set of angles congruent with sides on each side congruent as well (look at the first four as an example of this.
Any more specific questions, feel free to ask!