4x^2+12x+9-2x^2-7x-15

The circle above has an area of 144 pi cm^2. What is the area of the blue sector? Use 3.14 for pi.

sineoko [7]

Answer:

150.72 cm^2

Step-by-step explanation:

The blue area has an angle of 120 degrees, and 120/360 = 1/3, which shows that the blue area is 1/3 of the circle. In that case, the blue area is just 144pi/3. That simplifies to 48 pi.

48*3.14 = 150.72

8 0

4 years ago

Gabriella needs a mason and must decide between 2 companies. For a service visit, Company A charges $65 to send a mason plus $30

Kamila [148]

So first we write out their respective charges
A=65+30x (x=hours of A)
B=30+47.5y (x= hours of B)

we want to know when A and B are equal so just set them to be equal

65+30x=30+47.5x
subtract 30 from both sides
35+30x=47.5x
multiplyboth sides by 2 to get rid of the nasty decimal
70+60x=95x
subtract 60x from both sides
70=35x
divide both sides by 35
2=x
they must work 2 hours for them to be equal

7 0

4 years ago

Read 2 more answers

Please help im stuck on this question

FrozenT [24]

Answer:

A

Step-by-step explanation:

Slope is the first y - the second y divided by the first x- the second x. Therefore we take -8-4= -12 and -7-0= -7. Using the formula, we get -12/-7. The negatives cancel out and we get 12/7 which is A.

3 0

3 years ago

What is the answer to this?

umka21 [38]

Answer:

-3

Step-by-step explanation:

Step 1: Define

∛(-b² + a)

<em>a</em> = -2

<em>b</em> = 5

Step 2: Substitute

∛[-(5)² + (-2)]

Step 3: Evaluate

∛(-25 - 2)

∛-27

-3

5 0

4 years ago

The mayor of a town has proposed a plan for the construction of an adjoining bridge. A political study took a sample of 1700 vot

lara [203]

Answer:

$z=\frac{0.66 -0.63}{\sqrt{\frac{0.63(1-0.63)}{1700}}}=2.562$

$p_v =P(z>2.562)=0.0052$

So the p value obtained was a very low value and using the significance level given $\alpha=0.02$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that at 2% of significance the proportion of voters that favored construction is higher than 0.63 or 63%.

Step-by-step explanation:

Data given and notation

n=1700 represent the random sample taken

$\hat p=0.66$ estimated proportion of voters that favored construction

$p_o=0.63$ is the value that we want to test

$\alpha=0.02$ represent the significance level

Confidence=98% or 0.98

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to test the claim that percentage of residents who favor construction is more than 63%.:

Null hypothesis: $p \leq 0.63$

Alternative hypothesis: $p > 0.63$

When we conduct a proportion test we need to use the z statisitc, and the is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

Calculate the statistic

Since we have all the info requires we can replace in formula (1) like this:

$z=\frac{0.66 -0.63}{\sqrt{\frac{0.63(1-0.63)}{1700}}}=2.562$

Statistical decision

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.

The significance level provided $\alpha=0.02$ . The next step would be calculate the p value for this test.

Since is a right tailed test the p value would be:

$p_v =P(z>2.562)=0.0052$

So the p value obtained was a very low value and using the significance level given $\alpha=0.02$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that at 2% of significance the proportion of voters that favored construction is higher than 0.63 or 63%.

7 0

3 years ago