25,600 will be the bacteria population after doubling every 30 minutes for 3 hours.
Answer: The equation of the parabola is
.
Explanation:
It is given that the focus of the parabola is (-5,-5) and the directrix is y=7.
The standard form of the parabola is,

Where y=k-p is directrix and (h,k+p) is the focus.
Since focus is given,

On comparing,

.... (1)
The directrix is y=7.
.... (2)
Add equation (1) and (2),


Put this value in (1).

Put p= -6, h= -5 and k=1 in the standard form of the parabola.


Therefore, the equation of parabola is
.
Answer:
D.2.58
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
That is z with a pvalue of
, so Z = 2.58.
The answer is given by option D.
Mrs. Clark had one hundred pencils, and wanted to divide them evenly upon the ten students in her class. How many pencils should each student have?
To solve:
Divide 100 pencils by 10 students.
Answer:
10 pencils.