Algebra II help I'm struggling

Questions 2-7 will all be in regards to this data set:Observation X Y1 20 302 23 353 28 404 26 385 24 376 32 457 35 508 24 349 3

Tomtit [17]

Answer:

r =0.4437

Step-by-step explanation:

We have the follwoing dataset:

X: 20,23,53,4,24,32,35,24,31,23

Y: 30,35,40,38,37,45,50,34,42,32

n=10

The correlation coefficient is a "statistical measure that calculates the strength of the relationship between the relative movements of two variables". It's denoted by r and its always between -1 and 1.

And in order to calculate the correlation coefficient we can use this formula:

$r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}$

For our case we have this:

n=10 $\sum x = 269, \sum y = 383, \sum xy = 10609, \sum x^2 =8645, \sum y^2 =15007$

Th excel figure attached shows the calculations for each sum.

$r=\frac{10(10609)-(269)(383)}{\sqrt{[10(8645) -(269)^2][10(15007) -(383)^2]}}=0.4437$

So then the correlation coefficient would be r =0.4437

3 0

3 years ago

Directions : Factor each of the following Differences of two squares and write your answer together with solution

N76 [4]

$\huge \boxed{\mathfrak{Question} \downarrow}$

Factor each of the following differences of two squares and write your answer together with solution.

$\large \boxed{\mathbb{ANSWER\: WITH\: EXPLANATION} \downarrow}$

$\sf \: x ^ { 2 } - 36$

Rewrite $\sf\:x^{2}-36 as x^{2}-6^{2}$ . The difference of squares can be factored using the rule: $\sf\: a^{2}-b^{2}=\left(a-b\right)\left(a+b\right)$ .

$\boxed{ \boxed{ \bf\left(x-6\right)\left(x+6\right) }}$

__________________

$\sf \: 49 - x ^ { 2 }$

Rewrite 49-x² as 7²-x². The difference of squares can be factored using the rule: $\sf\:a^{2}-b^{2}=\left(a-b\right)\left(a+b\right)$ .

$\sf \: \left(7-x\right)\left(7+x\right)$

Reorder the terms.

$\boxed{ \boxed{ \bf\left(-x+7\right)\left(x+7\right) }}$

__________________

$\sf \: 81 - c ^ { 2 }$

Rewrite 81-c²as 9²-c². The difference of squares can be factored using the rule: $\sf\:a^{2}-b^{2}=\left(a-b\right)\left(a+b\right)$ .

$\sf\left(9-c\right)\left(9+c\right)$

Reorder the terms.

$\boxed{ \boxed{ \bf\left(-c+9\right)\left(c+9\right) }}$

__________________

$\sf \: m ^ { 2 } n ^ { 2 } - 1$

Rewrite m²n² - 1 as $\sf\left(mn\right)^{2}-1^{2}$ . The difference of squares can be factored using the rule: $\sf\:a^{2}-b^{2}=\left(a-b\right)\left(a+b\right)$ .

$\boxed{ \boxed{ \bf\left(mn-1\right)\left(mn+1\right) }}$

4 0

3 years ago

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What is the length of the unknown leg in the right triangle? A right triangle has a side with length 20 meters, hypotenuse with

galben [10]

The length of the unknown leg of the triangle is 15 m.

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

Length of one leg = 20 m

Length of the hypotenuse= 25m

As it is a right angled triangle we can use pythogoras theorem.

Let the unknown length be y

(20) (20) + y(y) = (25) (25)

400 + y(y) = 625

y(y) = 225

y = √225

y = 15

The length of the unknown leg is 15 m.

6 0

3 years ago

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Suppose we have a bag with $10$ slips of paper in it. Eight slips have a $3$ on them and the other two have a $9$ on them. How m

8_murik_8 [283]

Value of the given statement:

4.36
5
6
38

<h3>What is Probability?</h3>

The area of mathematics known as probability deals with numerical descriptions of how likely it is for an event to happen or for a claim to be true. A number between 0 and 1 is the probability of an event, where, broadly speaking, 0 denotes the event's impossibility and 1 denotes its certainty.

According to the given information:

1) There are a total of 10 slips after adding.

8 slip with 3 on it

2 slips with 9 on it

value = Probability of 3 x 3 plus Probability of 9 x 9.

= (8 / 11) x 3 + (2/ 11) x 9

24 / 11 + 24 / 11 = 4.36

2 )No of total slips after addition = 12

8 slip with 3 on it

4 slips with 9 on it

value = Probability of 3 x 3 plus Probability of 9 x 9.

= (8 / 12) x 3 + (4 / 12) x 9

2 + 3 = 5

3 )Let n be the required number

No of total slips after addition = 10+n

8 slip with 3 on it

2 + n slips with 9 on it

value = Probability of 3 x 3 plus Probability of 9 x 9.

= (8 / 10+n ) x 3 + (2+n / 10+n ) x 9 = 6

24 + 18 + 9n / 10 + n = 6

42 + 9n = 60 + 6n

3 n = 18

n = 6

4 )Let n be the required number

No of total slips after addition = 10+n

8 slip with 3 on it

2 + n slips with 9 on it

expectation value = probability of 3 x 3 + probability of 9 x 9

= (8 / 10+n ) x 3 + (2+n / 10+n ) x 9 = 8

24 + 18 + 9n / 10 + n = 8

42 + 9n = 80 + 8n

n = 38

Minimum of 38 has to be added .

To know more about Probability visit:

brainly.com/question/17487084

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I understand that the question you are looking for is:

1:Suppose we have a bag with $10$ slips of paper in it. Eight slips have a $3$ on them and the other two have a $9$ on them. What is the expected value of the number shown if we add one additional $9$ to the bag? 2:Suppose we have a bag with $10$ slips of paper in it. Eight slips have a $3$ on them and the other two have a $9$ on them. What is the expected value of the number shown if we add two additional $9$'s (instead of just one) to the bag? 3:Suppose we have a bag with $10$ slips of paper in it. Eight slips have a $3$ on them and the other two have a $9$ on them. How many $9$'s do we have to add to make the expected value equal to $6$? 4:Suppose we have a bag with $10$ slips of paper in it. Eight slips have a $3$ on them and the other two have a $9$ on them. How many $9$'s do I have to add before the expected value is at least $8$?

4 0

2 years ago

Arnold's entire workout consisted of 10 minutes of warm up exercise, 25 minutes of lifting weights, and 15 minutes on the treadm

lord [1]

Add all the times together:

10 + 25 + 15 = 50 minutes total.

For the ratio divide the time for weights by total time:

25/50 which reduces to 1/2

The ratio is 1/2

5 0

3 years ago

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