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3 years ago

(2x+5y-z)+(-6x-4y+7z)

Mathematics

1 answer:

11111nata11111 [884]3 years ago

8 0

Answer:

-4x + y + 6z

Step-by-step explanation:

2x + 5y - z + (-6x - 4y + 7z) < distribute positive 1 to (-6x - 4y + 7z)

2x + 5y - z - 6x - 4y + 7z < combine like terms to get the answer

2x - 6x = -4x

5y - 4y = y

-z + 7z = 6z

our new expression is:

-4x + y + 6z we cannot simplify this any further, so this is our answer

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Which equation best matches the graph shown below?

n200080 [17]

Answer:

y= 0.2(x+1)^2+5 (Bottom left answer)

Step-by-step explanation:

Hope this helps :)

6 0

2 years ago

Some scientists believe alcoholism is linked to social isolation. One measure of social isolation is marital status. A study of

frez [133]

Answer:

1) H0: There is independence between the marital status and the diagnostic of alcoholic

H1: There is association between the marital status and the diagnostic of alcoholic

2) The statistic to check the hypothesis is given by:

$\sum_{i=1}^n \frac{(O_i -E_i)^2}{E_i}$

3) $\chi^2 = \frac{(21-33.143)^2}{33.143}+\frac{(37-41.429)^2}{41.429}+\frac{(58-41.429)^2}{41.429}+\frac{(59-46.857)^2}{46.857}+\frac{(63-58.571)^2}{58.571}+\frac{(42-58.571)^2}{58.571} =19.72$

4) $df=(rows-1)(cols-1)=(3-1)(2-1)=2$

And we can calculate the p value given by:

$p_v = P(\chi^2_{2} >19.72)=5.22x10^{-5}$

And we can find the p value using the following excel code:

"=1-CHISQ.DIST(19.72,2,TRUE)"

Since the p value is lower than the significance level so then we can reject the null hypothesis at 5% of significance, and we can conclude that we have association between the two variables analyzed.

Step-by-step explanation:

A chi-square goodness of fit test "determines if a sample data matches a population".

A chi-square test for independence "compares two variables in a contingency table to see if they are related. In a more general sense, it tests to see whether distributions of categorical variables differ from each another".

Assume the following dataset:

Diag. Alcoholic Undiagnosed Alcoholic Not alcoholic Total

Married 21 37 58 116

Not Married 59 63 42 164

Total 80 100 100 280

Part 1

We need to conduct a chi square test in order to check the following hypothesis:

H0: There is independence between the marital status and the diagnostic of alcoholic

H1: There is association between the marital status and the diagnostic of alcoholic

The level os significance assumed for this case is $\alpha=0.05$

Part 2

The statistic to check the hypothesis is given by:

$\sum_{i=1}^n \frac{(O_i -E_i)^2}{E_i}$

Part 3

The table given represent the observed values, we just need to calculate the expected values with the following formula $E_i = \frac{total col * total row}{grand total}$

And the calculations are given by:

$E_{1} =\frac{80*116}{280}=33.143$

$E_{2} =\frac{100*116}{280}=41.429$

$E_{3} =\frac{100*116}{280}=41.429$

$E_{4} =\frac{80*164}{280}=46.857$

$E_{5} =\frac{100*164}{280}=58.571$

$E_{6} =\frac{100*164}{280}=58.571$

And the expected values are given by:

Diag. Alcoholic Undiagnosed Alcoholic Not alcoholic Total

Married 33.143 41.429 41.429 116

Not Married 46.857 58.571 58.571 164

Total 80 100 100 280

And now we can calculate the statistic:

$\chi^2 = \frac{(21-33.143)^2}{33.143}+\frac{(37-41.429)^2}{41.429}+\frac{(58-41.429)^2}{41.429}+\frac{(59-46.857)^2}{46.857}+\frac{(63-58.571)^2}{58.571}+\frac{(42-58.571)^2}{58.571} =19.72$

Part 4

Now we can calculate the degrees of freedom for the statistic given by:

$df=(rows-1)(cols-1)=(3-1)(2-1)=2$

And we can calculate the p value given by:

$p_v = P(\chi^2_{2} >19.72)=5.22x10^{-5}$

And we can find the p value using the following excel code:

"=1-CHISQ.DIST(19.72,2,TRUE)"

7 0

3 years ago

How can you tell that the data in the table is function or not?

stealth61 [152]

that is not a function, because there are two outputs for three. two inputs can have one output, but one input cant have two outputs.

6 0

3 years ago

Is a function or not

Anna71 [15]

Answer:

that is indeed a function

Step-by-step explanation:

6 0

2 years ago

Read 2 more answers

Please help me with this homework

snow_lady [41]

Answer:

10.44 m

Step-by-step explanation:

Solve this as a triange. The base is 3m and the perpendicular is 10m. The angle between the base and wall is 90° so it will be a right angled triangle.

Solve this by Pythagoras theorm:

let length of ladder is c

base is b

And perpendicular is a

Acc to Pythagoras theorem:

C² = a² + b²

C² = 10² + 3²

C² = 100 + 9

C² = 109

√C² = √109

C = 10.44m

8 0

2 years ago