Twenty percent of what number is equal to five percent of 680

Let L be the line with parametric equations x=2+t, y=1-t, z=1+3t.Let v=(1,2,0).Find vectors w1 and w2 such that v= w1 + w2, and

charle [14.2K]

Answer:

w1 = (-1/11, 1/11, -3/11)

w2 = (12/11, 21/11, 3/11)

Step-by-step explanation:

Direction ratio of w1 = Direction ratio of L (because parallel) = K+(1, -1, 3)

Let <a,b,c> be direction ratio of w2.

Then, <a,b,c>. <1,-1,3> = 0

a-b+3c = 0

v = w1 + w2

(1, 2, 0) = k(1, -1, 3) + (a, b, c)

a + k = 1

b - K = 2

c - 3k = 0

Solving 4 equations, a = 12/11, b= 21/11, c = 3/11, k=-1/11

So, w1 = -1/11(1, -1 ,3) = (-1/11, 1/11, -3/11)

w2 = (12/11, 21/11, 3/11)

6 0

1 year ago

SAT Writing scores are normally distributed with a mean of 491 and a standard deviation of 113.A university plans to send letter

Sholpan [36]

Answer:

$z=1.405$

And if we solve for a we got

$a=491 +1.405*113=649.765$

So the value of height that separates the bottom 92% of data from the top 8% is 649.765.

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the scores of a population, and for this case we know the distribution for X is given by:

$X \sim N(491,113)$

Where $\mu=491$ and $\sigma=113$

For this part we want to find a value a, such that we satisfy this condition:

$P(X>a)=0.08$ (a)

$P(X$ (b)

Both conditions are equivalent on this case. We can use the z score again in order to find the value a.

As we can see on the figure attached the z value that satisfy the condition with 0.92 of the area on the left and 0.08 of the area on the right it's z=1.405. On this case P(Z<1.405)=0.92 and P(z>0.92)=0.08

If we use condition (b) from previous we have this:

$P(X$

$P(z$

But we know which value of z satisfy the previous equation so then we can do this:

$z=1.405$

And if we solve for a we got

$a=491 +1.405*113=649.765$

So the value of height that separates the bottom 92% of data from the top 8% is 649.765.

6 0

2 years ago

Part of a book fell out. The first page of this part has number 143. The last page has a number written with the same digits. Ho

Gnom [1K]

Answer:

142 pages

Step-by-step explanation:

The parameters given are

First page of part of the book available = 143

The last is numbered with the digits 143

Since the book is said to have been split into two parts with, we have that one part of the book starts from the beginning, while the other part continue from the first part stops

Number on the pages on the first part = from 1 to number on the first page on the second part - 1

Hence, the part of the book available is the second part and the number of pages in the first part = 1 to 142 or 142 pages.

3 0

2 years ago

a national park charges $26 per adult and $16 per child for rafting down one of their two rivers. Write an algebraic expression

blondinia [14]

26a+16c would be the answer

5 0

2 years ago

Which graph can be used to find the solution(s) to 4x=-4x?

Elden [556K]

<h2>Answer:</h2>

The graph is shown in the Figure below

<h2>Step-by-step explanation:</h2>

In this exercise, we have an equation. On the left side we have a straight line with slope $m=4$ and there is no any y-intercept. On the right side, on the other had, we also have a straight line, but the slope here is $m=-4$ . Therefore, by plotting these two straight lines, we have that the solution is the origin, that is, the point $(0, 0)$ .

6 0

1 year ago

Read 2 more answers