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3 years ago

How to do this ? Don’t understand it

Mathematics

1 answer:

riadik2000 [5.3K]3 years ago

7 0

X=y+3
-5x-4y=30
-------------------
Substitute y + 3 for x in -5x-4y=30
-5(y+3)-4y=30
-9y-15=30
----------------------------
Add 15 to each side
-9y-15+15=30+15
-9y = 45
-----------------------------------
Divide each side by -9
-9y ÷ -9 = 45 ÷ -9
y = -5
Now we solve for x
====================================================================
Substitute -5 for y in x = y + 3
x=-5+3
x = -2
----------------------
(-2,-5) is your answer

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Compound probability can be greater than 1. Trueor False?

vivado [14]

Answer:

False

Step-by-step explanation:

Compound probability is the likeliness of two or more events occurring together.

Probability can never be greater than 1 whatever form it takes. Its values range between zero and one. When a probability is multiplied with any particular number such as n ( number of trials) we get expected value or whatever the formula says but probability itself is never greater than 1.

If we get the answer of any question where the found probability is greater than 1 the answer is wrong because probability is not greater than 1.

The sum of all probabilities may be nearly equal to 1 like 0.99999 etc.

8 0

4 years ago

Need help please asap due 5:30

notsponge [240]

Answer:

5 30 is my guess

Step-by-step explanation:

3 0

3 years ago

There are four blue marbles, an unknown number of red (r) marbles, and six yellow marbles in a bag. Which expression represents

MAXImum [283]

Answer:

There are a total of 4 + r + 6 marbles in the bag

The probability of a blue is $\frac{4}{10+r}$

The probability of a red is $\frac{r}{10+r}$

The probability of choosing a blue, replacing it and then a red is

$\frac{4}{10+r}$ × $\frac{r}{10+r}$ = [tex]\frac{4r}{100+20r+ r^{2} /[tex]

Step-by-step explanation:

6 0

3 years ago

What value of x makes the equation 4(5 - 7x) = 6 - 12x true?

Lemur [1.5K]

Answer:

4(5 - 7x) = 6 - 12

20-28x=6-12x

Subtract 20 from both sides

20-28x-20=6-12x-20

Simplify

-28x=-12x-14

Add 12x to both sides

-28+12x=-12x=-12x-14+12x

Simplify

-16x=-14

Divide both sides by -16

-16/-16 = -14/-16

Anw

7/8= 0.875

7 0

3 years ago

In 2008, there were 507 children in Arizona out of 32,601 who were diagnosed with Autism Spectrum Disorder (ASD) ("Autism and de

Naily [24]

Answer:

$z=\frac{0.0156-0.0114}{\sqrt{0.01554(1-0.01554)(\frac{1}{32601}+\frac{1}{88})}}=0.318$

$p_v =P(Z>0.318)=0.375$

So the p value is a very high value and using the significance level provided $\alpha=0.01$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can say the the proportion of children diagnosed with Autism Spectrum Disorder (ASD) in arizona is not significantly higher than the national incident rate at 1% of significance.

Step-by-step explanation:

Data given and notation

$X_{1}=507$ represent the number of children diagnosed with Autism Spectrum Disorder (ASD) in Arizona

$n_{1}=32601$ sample elected from arizona

$\hat p_{1}=\frac{507}{32601} =0.0156$ represent the proportion of children diagnosed with Autism Spectrum Disorder (ASD) in arizona

$p_{2}=\frac{1}{88}= 0.0114$ represent the proportion of children diagnosed with Autism Spectrum Disorder (ASD) in the nation

z would represent the statistic (variable of interest)

$p_v$ represent the value for the test (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if that the incident of ASD is more in Arizona than nationally, the system of hypothesis are:

Null hypothesis: $p_{1} \leq p_{2}$

Alternative hypothesis: $p_{1} > p_{2}$

We need to apply a z test to compare proportions, and the statistic is given by:

$z=\frac{p_{1}-p_{2}}{\sqrt{\hat p (1-\hat p)(\frac{1}{n_{1}}+\frac{1}{n_{2}})}}$ (1)

Where $\hat p=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{507+1}{32601 +88}=0.01554$

Calculate the statistic

Replacing in formula (1) the values obtained we got this:

$z=\frac{0.0156-0.0114}{\sqrt{0.01554(1-0.01554)(\frac{1}{32601}+\frac{1}{88})}}=0.318$

Statistical decision

The significance level provided is $\alpha=0.01$ , and we can calculate the p value for this test.

Since is a one right sided test the p value would be:

$p_v =P(Z>0.318)=0.375$

5 0

3 years ago