Can someone help me please

What are the steps to solve -2n-(9-10n) ?

larisa86 [58]

(9+10n)(9-10n) Final result : (10n + 9) • (9 - 10n)

Step by step solution : Step 1 :Final result : (10n + 9) • (9 - 10n)

8 0

2 years ago

Help, please the question and thank you

Ann [662]

Answer:

sorry i dont know it but i can help you with other subjects like history?

Step-by-step explanation:

4 0

2 years ago

Read 2 more answers

Plz help me

drek231 [11]

Answer:

1. Circumference because the other two aren’t the correct answers and don’t sound like the correct answers.

2. 35 is the radius for the blue car

3. 20.1 is the radius for the green car

4. The difference between both cars radii is that one has a larger radius than the other

Step-by-step explanation:

Hope This Helps!

6 0

2 years ago

Read 2 more answers

IF x+y=5 and x-2y=-4 find the value of x and y

Serggg [28]

Answer:

x = 2, y = 3

Step-by-step explanation:

x + y = 5

Shift y to the other side and change to (-y).

x = 5 - y --- Equation 1

x - 2y = -4 --- Equation 2

Substitute x = 5 - y into Equation 2:

x - 2y = -4

5 - y - 2y = -4

Shift 5 to the other side and change to (-5).

-y - 2y = -4 - 5

Evaluate like terms.

-3y = -9

Divide both sides by -3.

y = -9 ÷ -3

y = 3

Substitute y = 3 into Equation 1:

x = 5 - y

x = 5 - 3

x = 2

4 0

3 years ago

A researcher wishes to see if the five ways (drinking decaffeinated beverages, taking a nap, going for a walk, eating a sugary s

e-lub [12.9K]

Answer:

$\chi^2 = \frac{(21-12)^2}{12}+\frac{(16-12)^2}{12}+\frac{(10-12)^2}{12}+\frac{(8-12)^2}{12}+\frac{(5-12)^2}{12}=13.833$

$p_v = P(\chi^2_{4} >13.833)=0.00785$

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

"=1-CHISQ.DIST(13.833,4,TRUE)"

Since the p value is lower than the significance level we can reject the null hypothesis at 5% of significance, and we can conclude that the drowsiness are NOT equally distributed among office workers .

Step-by-step explanation:

Previous concepts

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:

Method Beverage Nap Walk Snack Other

Number 21 16 10 8 5

The total on this case is 60

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

H0: Drowsiness are equally distributed among office workers

H1: Drowsiness IS NOT equally distributed among office workers

The level of significance assumed for this case is $\alpha=0.1$

The statistic to check the hypothesis is given by:

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

The table given represent the observed values, we just need to calculate the expected values with the following formula $E_i = \frac{total}{5}$

And the calculations are given by:

$E_{Beverage} =\frac{60}{5}=12$

$E_{Nap} =\frac{60}{5}=12$

$E_{Walk} =\frac{60}{5}=12$

$E_{Snack} =\frac{60}{5}=12$

$E_{Other} =\frac{60}{5}=12$

And the expected values are given by:

Method Beverage Nap Walk Snack Other

Number 12 12 12 12 12

And now we can calculate the statistic:

$\chi^2 = \frac{(21-12)^2}{12}+\frac{(16-12)^2}{12}+\frac{(10-12)^2}{12}+\frac{(8-12)^2}{12}+\frac{(5-12)^2}{12}=13.833$

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

$df=(catgories-1)=(5-1)=4$

And we can calculate the p value given by:

$p_v = P(\chi^2_{4} >13.833)=0.00785$

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

"=1-CHISQ.DIST(13.833,4,TRUE)"

Since the p value is lower than the significance level we can reject the null hypothesis at 5% of significance, and we can conclude that the drowsiness are NOT equally distributed among office workers .

7 0

3 years ago