Answer:
D. Only one cleaning product was asked about in the survey.
Any given company can use more than one cleaning product or even use a combination of different cleaning products. The question was not specific enough, since it should have probably asked which cleaning products are used and which ones are used more frequently.
Step-by-step explanation:
the other options are wrong because:
- A. Only 50 cleaning services were surveyed. ⇒ This actually would increase the validity of the claim because it satisfies the the condition for a valid confidence interval [np and n(1 - p) are larger than 10]-
- B. Cleaning services were selected at random. ⇒ This actually would increase the validity of the claim.
- C. A well-known company conducted the survey. ⇒ This actually would increase the validity of the claim.
The parabola with vertex at (0,0) and directrix at x=-4, will open towards the right.
<h3>What is a directrix?</h3>
A parabola is a collection of points on a plane that are all at the same distance from a particular point and line. The point is called the focus of the parabola while the line is called the directrix. The directrix is perpendicular to a parabola's axis of symmetry and does not contact it.
As we know that the directrix is perpendicular to the axis of the parabola, now since the directrix is at x=-4, the parabola will be horizontal and will be opening either towards the left or the right.
As it is given that the vertex of the parabola is at (0,0) and we know that the parabola can not touch the directrix, therefore, the parabola's vertex will be at (0,0) and will open towards the right side. As shown below.
Hence, the parabola with vertex at (0,0) and directrix at x=-4, will open towards the right.
Learn more about Directrix:
brainly.com/question/2629634
If x represents the length of the box, then 42-x will be the girth. Since the largest area for a given girth is that of a square, the side length of the square cross section is (42 -x)/4.
The volume as a function of package length is then
.. v(x) = x((42-x)/4)^2
This has a maximum at x=14. The corresponding volume is 686 in^3.
Answer:
Step-by-step explanation:
To solve using completing square, we need to write the equation as x2+3x=17.
The next step is to add a number such that the square can be completed. The number must be equal to (b/2a)^2, so here it will be (3/2)^2 = 9/4
The equation then becomes x2+3x+(9/4)=17+(9/4).
Solving it further will get you the final answer