Answer:
100
Step-by-step explanation:
I counted
Answer:
y = -7, y = -3
Step-by-step explanation:
(y - 3)² = 2y² + 4y + 30
expand:
y² - 6y + 9 = 2y² + 4y + 30
subtract 30 from both sides
y² - 6y + 9 - 30= 2y² + 4y + 30 - 30
simplify:
y² - 6y - 21 = 2y² + 4y
subtract 4y from both sides
y² - 6y - 21 -4y = 2y² + 4y - 4y
simplify:
y² - 10y - 21 = 2y²
subtract 2y² from both sides
y² - 10y - 21 - 2y² = 2y² - 2y²
simplify:
-y² - 10y - 21 = 0
solve y by quadratic equation
- (-10) ± √ (-10² - 4(-1)(21)
y = --------------------------------------
2(-1)
y = -7, y = -3
Answer:
The number of students who scored more than 90 points is 750.
Step-by-step explanation:
Quartiles are statistical measures that the divide the data into four groups.
The first quartile (Q₁) indicates that 25% of the observation are less than or equal to Q₁.
The second quartile (Q₂) indicates that 50% of the observation are less than or equal to Q₂.
The third quartile (Q₃) indicates that 75% of the observation are less than or equal to Q₃.
It is provided that the first quartile is at 90 points.
That is, P (X ≤ 90) = 0.25.
The probability that a student scores more than 90 points is:
P (X > 90) = 1 - P (X ≤ 90)
= 1 - 0.25
= 0.75
The number of students who scored more than 90 points is: 1000 × 0.75 = 750.
The midpoint formula is ( x + x / 2, y + y / 2)
so....
6+ 2 = 8 / 2 = 4
4 + 8 = 12 / 2 = 6
the midpoint is (4, 6)
Its not that hard... whats the question