Using the mean concept, it is found that we will need 15 more points to bring up his average up to 90%.
The mean of a data-set is the <u>sum of all observations divided by the number of observations</u>.
In this problem:
- In the first 5 observations, total of 21 out of 25 points, hence the mean for these observations is
. - In the next n observations, mean of 1.
Hence, the mean is:
![M = \frac{0.84(5) + n}{5 + n} = \frac{4.2 + n}{5 + n}](https://tex.z-dn.net/?f=M%20%3D%20%5Cfrac%7B0.84%285%29%20%2B%20n%7D%7B5%20%2B%20n%7D%20%3D%20%5Cfrac%7B4.2%20%2B%20n%7D%7B5%20%2B%20n%7D)
We want the mean to be of 0.9, thus:
![M = 0.9](https://tex.z-dn.net/?f=M%20%3D%200.9)
![\frac{4.2 + n}{5 + n} = 0.9](https://tex.z-dn.net/?f=%5Cfrac%7B4.2%20%2B%20n%7D%7B5%20%2B%20n%7D%20%3D%200.9)
![4.2 + n = 0.9n + 4.5](https://tex.z-dn.net/?f=4.2%20%2B%20n%20%3D%200.9n%20%2B%204.5)
![0.1n = 0.3](https://tex.z-dn.net/?f=0.1n%20%3D%200.3)
![n = \frac{0.3}{0.1}](https://tex.z-dn.net/?f=n%20%3D%20%5Cfrac%7B0.3%7D%7B0.1%7D)
3 more testes are need, each worth 5 points, hence, 15 more points are needed to bring up his average up to 90%.
A similar problem is given at brainly.com/question/25323941
Answer:
1. An Experimental
2. Dependent
3. Independent
Step-by-step explanation:
Considering the description of how the research was carried out, it can be concluded that This study is an example of AN EXPERIMENTAL study. This because the researcher is trying to study the effectiveness of a new drug for lowering cholesterol
The difference in cholesterol level is the DEPENDENT variable. This is because the difference in cholesterol level is what the researcher wants to determine.
The treatment with a drug or placebo is the INDEPENDENT variable. This is because this is what the researcher manipulates to determine the difference in cholesterol level which is the dependent variable in this experimental study.
Answer:
B has a higer probability
Step-by-step explanation:
Scale factor is 2
30/15 = 2
20/10 = 2
Answer:
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