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2 years ago

A student is finding the measures of the angles in a triangle that have the ratio 4:4:7. Find the mistake and correct it.

Mathematics

1 answer:

7nadin3 [17]2 years ago

8 0

suppose 4:4:7 be 4x, 4x, 7x

or, 15x = 180°

or, X = 180/15

or, X = 12

therefore,

4x = 4x12= 48

4x= 4x12= 48

7x= 7x12= 84

so if you plus all of them you get 180

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Guys help me please.<br> How to solve it?

pentagon [3]

I don’t have a calculator right now but a triangle always adds up to 180 degrees so yeah

7 0

3 years ago

Read 2 more answers

Assume the sample variances to be continuous measurements. Find the probability that a random sample of 25observations, from a n

konstantin123 [22]

Answer:

a) $P(4S^2 > 4*9.1) = P(\chi^2_{24} >36.4) = 0.0502$

b) $P(13.848$ Step-by-step explanation:

Previous concepts

The Chi Square distribution is the distribution of the sum of squared standard normal deviates .

For this case we assume that the sample variance is given by $S^2$ and we select a random sample of size n from a normal population with a population variance $\sigma^2$ . And we define the following statistic:

$T = \frac{(n-1) S^2}{\sigma^2}$

And the distribution for this statistic is $T \sim \chi^2_{n-1}$

For this case we know that n =25 and $\sigma^2 = 6$ so then our statistic would be given by:

$\chi^2 = \frac{(n-1)S^2}{\sigma^2}=\frac{24 S^2}{6}= 4S^2$

With 25-1 =24 degrees of freedom.

Solution to the problem

Part a

For this case we want this probability:

$P(S^2 > 9.1)$

And we can multiply the inequality by 4 on both sides and we got:

$P(4S^2 > 4*9.1) = P(\chi^2_{24} >36.4) = 0.0502$

And we can use the following excel code to find it: "=1-CHISQ.DIST(36.4,24,TRUE)"

Part b

For this case we want this probability:

$P(3.462 < S^2$

If we multiply the inequality by 4 on all the terms we got:

$P(3.462*4 < 4S^2 < 4*10.745)= P(13.848< \chi^2$ And we can find this probability like this: $P(13.848$ And we use the following code to find the answer in excel: "=CHISQ.DIST(42.98,24,TRUE)-CHISQ.DIST(13.848,24,TRUE)"

8 0

3 years ago

What’s 3.8 - (-7.45)

Varvara68 [4.7K]

it is 11.25................................

6 0

3 years ago

3 years ago a father was 3 times as old as his son, in five years time he will be twice as old as his son, what will be the sum

ivolga24 [154]

Answer: 46 years

Step-by-step explanation:

Let the father's age be x and the son's age be y, then 3 years ago:

Father = x - 3

son = y - 3

Then , from the first statement :

x - 3 = 3 ( y - 3 )

x - 3 = 3y - 9

x = 3y - 9 + 3

x = 3y - 6 .......................................... equation 1

In five years time

father = x + 5

son = y + 5

Then , from the second statement

x + 5 = 2 ( y + 5 )

x + 5 = 2y + 10

x = 2y + 10 - 5

x = 2y + 5 ........................ equation 2

Equating equation 1 and 2 , we have

3y -6 = 2y + 5

add 6 to both sides

3y = 2y + 5 + 6

subtract 2y from both sides

3y - 2y = 11

y = 11

substitute y = 11 into equation 1 to find the value of x

x = 3y - 6

x = 3(11) - 6

x = 33 - 6

x = 27

This means that the father is presently 27 years and the son is presently 11 years.

In four years time

father = 27 + 4 = 31

son = 11 + 4 = 15

sum of their ages in four years time will be

31 + 15 = 46 years

5 0

3 years ago

Read 2 more answers

I really need help I’m very confused

Vaselesa [24]

Answer:

10: -11n^5

12: 6k^2 -6k+7

Step-by-step explanation:

Ok so what your gonna do is add or subtract the ones with the same exponent.

so -15+4= -11 since they are both n^5 you can add them so your answer is:

-11n^2

now you have 8k^2-k-5k+7-2k. so you are gonna rearrange them so the same exponents are together.(keep the sign in front in front, if no sign it is positive)

8k^2-2k^2-5k-k+7

add like exponents

6k^2-6k+7

6 0

3 years ago