Answer:
y = - (x - 5)² + 7
Step-by-step explanation:
The equation of a quadratic in vertex form is
y = a(x - h)² + k
where (h, k ) are the coordinates of the vertex and a is a multiplier
Here (h, k ) = (5, 7 ) , then
y = a(x - 5)² + 7
To find a substitute (10, - 3 ) into the equation
- 3 = a(10 - 5)² + 7 ( subtract 7 from both sides )
- 10 = 5²a = 25a ( divide both sides by 25 )
= a , that is
a = -
y = - (x - 5)² + 7 ← in vertex form
Answer:
Step-by-step explanation:
general slope intercept equation of a straight line is given as
where m is slope and b is y-intercept
here
and
Answer: 208.
Step-by-step explanation:
The formula to find the minimum sample size is given by :-
(1)
, where z* = critical z-value (two tailed).
= Standard deviation ( from prior study ) and E = Margin of error.
As per given , we have
Margin of error : E= 0.29
Confidence level = 85%
Significance level =
Using z-table , the critical value (two -tailed)=
As per previous study , Variance =
Now, the required minimum sample size = [Substitute the values in formula (1)]
[ Round to the next integer]
Hence, the minimum number of third graders that must be included in a sample = 208.