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:

We want the mean to be of 0.9, thus:





 
 
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:

Step-by-step explanation:
It can be found by integral.
First let's find the intersection points.

Only intersection point is x = 2.
And it is asked to find the area in the interval (2, 4).

We will use integration by parts.


 
        
             
        
        
        
Answer:

Step-by-step explanation:
 is essentially
 is essentially  (you are squaring
 (you are squaring  , so multiplying it by itself), so to simplify, you would need to distribute.
, so multiplying it by itself), so to simplify, you would need to distribute.
A good way to go about this is using the F.O.I.L. method, multiplying the First numbers in the parentheses, then the Outers, then Inners, and finally, Lasts.
 >>
 >>  >>
 >>  >>
 >> 
( )
) 
After doing so, you would end up with  , and after combining like terms,
, and after combining like terms,  .
.
To write the expression in standard form, though, just order the terms from highest to lowest power!
 
        
             
        
        
        
All three are similar
In ∆SUT and ∆VWX
- Two sides are similar and one angle is similar
So by SSA they are similar
In ∆PRQ and rest two
All angles are.
So
They are similar by AAA congruence