C. A survey of 70 teachers showed that 21 of them have a second job.
D. A survey of 80 teachers showed that 32 of them have a second job.
In math class, 4 students complete individual surveys to determine the percentage of high school teachers that have a second job. Which two surveys show proportional results?
A) A and B
B) B and D
C) A and D
D) B and C
Answer:
Correct option is:
D) B and C
Step-by-step explanation:
A. A survey of 110 teachers showed that 28 of them have a second job.
B. A survey of 90 teachers showed that 27 of them have a second job.
C. A survey of 70 teachers showed that 21 of them have a second job.
D. A survey of 80 teachers showed that 32 of them have a second job.
Percentage of teachers having second job is calculated by the formula:
So, percentage of second job teachers of survey A,B,C and D is:
A B C D
Percentage 25.45% 30% 30% 40%
Hence, two surveys that are proportional are
B and C
Hence, Correct option is:
D) B and C
f(x) = 2x2 – x + 1
f(x) = x2 + 2x – 1
f(x) = x2 – 2x + 1
we know that
The equation of the vertical parabola in vertex form is equal to
where
(h,k) is the vertex
The axis of symmetry is equal to the x-coordinate of the vertex
so
------> axis of symmetry of a vertical parabola
we will determine in each case the axis of symmetry to determine the solution
case A)
Convert to vertex form
Group terms that contain the same variable, and move the constant to the opposite side of the equation
Factor the leading coefficient
Complete the square. Remember to balance the equation by adding the same constants to each side
Rewrite as perfect squares
the vertex is the point
the axis of symmetry is
therefore
the function has an axis of symmetry at
case B)
Convert to vertex form
Group terms that contain the same variable, and move the constant to the opposite side of the equation
Factor the leading coefficient
Complete the square. Remember to balance the equation by adding the same constants to each side
Rewrite as perfect squares
the vertex is the point
the axis of symmetry is
therefore
the function does not have a symmetry axis in
case C)
Convert to vertex form
Group terms that contain the same variable, and move the constant to the opposite side of the equation
Complete the square. Remember to balance the equation by adding the same constants to each side
Rewrite as perfect squares
the vertex is the point
the axis of symmetry is
therefore
the function does not have a symmetry axis in
case D)
Convert to vertex form
Group terms that contain the same variable, and move the constant to the opposite side of the equation
Complete the square. Remember to balance the equation by adding the same constants to each side
Rewrite as perfect squares
the vertex is the point
the axis of symmetry is
therefore
the function does not have a symmetry axis in
the answer is