Answer:

Step-by-step explanation:
We will use the distance formula to solve.





<em>Read more about using the </em><em>distance formula</em><em> here: brainly.com/question/15691280</em>
Answer:
21
Step-by-step explanation:
Using<em> Simple Random Sampling</em>, we can estimate the sample size by the formula
where
n = sample size
Z = the z-score corresponding to the confidence level 99.5%
S = the assumed standard deviation = 3 seconds
e = margin of error = 2 seconds
<em>It is worth noticing that the higher the confidence level, the larger the sample should be.
</em>
The z-score corresponding to a confidence level of 99.5% can be obtained either with a table or the computer and equals
Z = 3.023
Replacing the values in our formula
So the size of the sample should be at least 21.
Answer:
300 points
Step-by-step explanation:
160 + 20 = 180
180 would have been 60 percent
180/60 = 300
300 would have been needed to pass
Proven by:
300 * 60% = 180
180 - 20 = 160
Answer:
x=3
Step-by-step explanation:
Since both triangles are similiar, this means they can have different sized sides, but they are just scaled versions of each other. This also means that no matter what sides they have, their angles are going to be the exact same
Knowing this, it helps to draw them out side by side so you can match them up easier. Both of them have a 90 degree angle, and more specifically they are 45-45-90 triangles (45-45-90 is a special right triangle). You can point this out since they give us a 90 degree angle and two angles that are congruent in the same triangle. In order for that to work, they HAVE to be 45-45-90
With this, we can find out what x equals. Since the two angles markings line up with the two side angles in the other triangle, we know that they are equal to each other.
we can use the equation 15x = 45, since 45 is what the side angle should equal.
now, we just divide 45 by 15, and we should get 3
so x = 3!
I hope this helps :)