HELP ASAP MARKING BRAINLIEST

Can someone help me write the equations and solve, please.

Novay_Z [31]

Answer:

Number 11: She has to add 5/36 of a cup

Number 12: The present costs $22,2

Number 13: 56,7 pounds is the weight of the package.

Number 14: You started with 40 muffins

Step-by-step explanation:

Number 11: 1/4 = 9/36 and 1/9 = 4/36

3*1/4 - 3*1/9 = 3*9/36 - 3*4/36 = 5/36

Number 12: 13,32/x= 3/5 ( or 0,6)

x = 13,32/0,6 = 22,2

Number 13: x * 5/7 = 40,5

x = 40,5/ (5/7) or 40,5 * 7/5 = 283,5/5 = 56,7

Number 14: 12/x = 3/10 (or 0,30)

x= 12/0,30 = 40

6 0

3 years ago

In early 2012, the Pew Internet and American Life Project asked a random sample of U.S. adults, "Do you ever ... use Twitter or

8090 [49]

Answer:

The confidence interval for the mean is given by the following formula:

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

And the confidence interval is given by:

(0.123, 0.177)

And for this case the interval contains the value 0.16, so then we can conclude at 5% of significance that the true proportion is not different from 0.16

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

Solution to the problem

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical value would be given by:

$z_{\alpha/2}=-1.96, z_{1-\alpha/2}=1.96$

The confidence interval for the mean is given by the following formula:

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

And the confidence interval is given by:

(0.123, 0.177)

And for this case the interval contains the value 0.16, so then we can conclude at 5% of significance that the true proportion is not different from 0.16

3 0

3 years ago

If a triangle with vertices A(-1, 4), B(-1, -2), C(2, -2) is dilated with a scale factor of 2 and a center of dilation at the or

givi [52]

Answer:

A' (-2,8) B' (-2,-4) C' (4,-4)

Step-by-step explanation:

Dilations Rule :

(x,y) → (kx,ky)

Scale factor = K

When your scale factor is more than one our triangle gets bigger. When your scale factor is less than one our triangle gets smaller.

( you plug in 2 in every point and those are your answers).

Remember negative times negative is positive and positive times negative is negative.

5 0

3 years ago

What is the slope of the line perpendicular to the line with equation 4x-5y+13=0

motikmotik

Answer:

m = - 5/4

Step-by-step explanation:

If two lines are perpendicular, their slopes are negative reciprocals, which means that their product is -1

We can write the equation

4*x - 5*y + 13 = 0

as: 5*y = 4*x + 13 or

y = (4/5)*x + 13 (1)

Equation (1) is the equation of a straight line in its slope point form, 4/5 is the slope, according to this the slope of a perpendicular line is

-5/4

4 0

3 years ago

Learning goal: to understand the rules for computing dot products. let vectors a=(2,1,−4), b=(−3,0,1), and c=(−1,−1,2). part a -

miv72 [106K]

For this case we have the following vectors:
$a = (2,1, -4)

b = (- 3,0,1)

c = (- 1, -1,2)$
The dot product of two vectors is a scalar.
The point product consists of multiplying component by component and then adding the result of the multiplication of each component.
For the product point of the vectors a and b we have:
$a.b = (2,1, -4). (- 3,0,1)

a.b = (2) (- 3) + (1) (0) + (-4) (1)

a.b = - 6 + 0 - 4

a.b = - 10$
Answer:
The product point of the vectors a and b is:
$a.b = - 10$

3 0

3 years ago