Answer:
30 students
Step-by-step explanation:
3 students = 10% of the class.
x students = 90% of the class.
(If more, less divides. Let x be the subject. Since we know 10% of the class already, we have to find the remaining 90% that is 100% - 10% = 90%.)
x = 90%/ 10% × 3 students. ( the percentage signs cancel out and so do the zero's.)
x= 9/1 × 3 students ( 9/1 is the same as 9)
x= 27 students
(To find the total, you must add the 10% of the students to the remaining 90% of the students in the class.)
Total number of students in the class = 27 students + 3 students
= 30 students
Answer:
With alpha 0.95 and 8 degrees of freedom χ²= 2.73
And with alpha 0.05 and 8 degrees of freedom χ²=15.51
Step-by-step explanation:
The significance level ∝ = 1- 0.9 = 0.1
But we need the area of the middle so we divide this significance level with 2
so that we get exactly the middle area .
Dividing 0.1/2= 0.05
So we will have two values for chi square
One with 0.9 + 0.05 = 0.95 alpha and one with 0.05 alpha . This is because the chi square is right tailed.
So with alpha 0.95 and 8 degrees of freedom χ²= 2.73
And with alpha 0.05 and 8 degrees of freedom χ²=15.51
This can be shown with a graph.
<span>x² + y² + 14x − 4y − 28 = 0
x² +14x +y² - 4y =28
x²+2*7x +7² -7² + y² - 2*2y +2² - 2² = 28
(x+7)² + (y-2)² -7²-2² =28
</span>(x+7)² + (y-2)²=28+49+4
(x+7)² + (y-2)² =81 is the answer.
Answer:
13
Step-by-step explanation:
We can add 1 to both sides of the second equation and divide by 2 to get
x = (y-1)/2
We can then substitute x in the first equation to get
(y-1)/2 + 7 = 2y
Multiply by 2
y-1 + 14 = 2y
Subtract y and combine like terms
y = 13
Answer:
C
Step-by-step explanation:
The pool raises 30 inches every 4 secounds
Therefore the equations to find the answer is 30 divided by 4 which equals 7.5
