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3 years ago

8

Name a three-dimensional shape that has four triangular faces and one rectangular face. Name a three-dimensional shaoe that has

three rectangular faces and two triangular faces.

1 answer:

rodikova [14]3 years ago

3 0

The answers would be pyramid and triangular prism.

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Which property justifies the statement below

yawa3891 [41]

Answer:

identify a property is the answer

4 0

3 years ago

Suppose that we wish to assess whether more than 60 percent of all U.S. households in a particular income class bought life insu

Yakvenalex [24]

Answer:

a) The probability is P=0.3982.

b) No. There is no enough evidence to say that the proportion of the population is not 0.6.

Step-by-step explanation:

a) In this question, we have a sample of the population, of size n=1000. To know what is the probability of observing a sample proportion that is at least 0.64 we have to know the parameters of the sampling distribution.

The parameters of the sampling distribution of the proportion will be:

$\mu=\pi=0.6\\\\ \sigma=\sqrt{\frac{\pi(1-\pi)}{N} } =\sqrt{\frac{0.6(1-0.6)}{1000} }= 0.0155$

With these parameters, we can calculate the z-value for p=0.64 as:

$z=\frac{p-\pi}{\sigma}=\frac{0.64-0.6}{0.0155}= 0.258$

Then, we can calculate the probability of having a sample with p≥0.64:

$P(p\geq0.64)=P(z\geq0.258)=0.3982$

b) To know if the proportion of the population is greater than 0.6 the rigth thing to do is perform a hypothesis test, in which we test the following hypothesis:

$H_0: \pi\leq0.6\\\\H_1:\pi>0.6$

If the null hypothesis is rejected, we can conclude that there is evidence that the proportion of the population is greater than 0.6.

First, we assume a significance level of 0.05.

Second, we calculate the z value:

$z=\frac{p-\pi-0.5/N}{\sigma} =\frac{0.64-0.6-0.5/1000}{0.0155} =\frac{0.0395}{0.0155} =2.54$

The P-value for this z is P=0.4. The P-value is greater than the significance level, what means that there is no evidence to reject the null hypothesis.

In other words, a sample mean of 0.64 is a quite probable value even if the proportion of the population is 0.6.

6 0

3 years ago

1. Find the perimeter of<br>15 cm<br>10 cm<br>18 cm

xz_007 [3.2K]

It’s 43 cm because you add all the sides

8 0

3 years ago

Read 2 more answers

I need help with part B plz help me asap

Sloan [31]

Answer:

see below PLEASE GIVE BRAINLIEST!!

Step-by-step explanation:

A) 2.40A ≦ 9.60

B) You can choose to purchase between 0 and 4 avacados. 4 is the maximum you can buy because 2.40 x 4 = 9.60 and that is all the money you have and more than 4 would make the equation incorrect. 0 is the least you can buy since you can't purchase a negative amount of something.

So, A ≦ 4

6 0

4 years ago

Consider the planes 4x+3y+4z=1 and 4x+4z=0. (A) Find the unique point P on the y−axis which is on both planes. ( 0 equation edit

Nana76 [90]

Answer:

Step-by-step explanation:

A) From the order of the exercise we already know that the intersection points lies on the Y-axis, so its coordinates are P(0;y;0). In order to find it, we only need to substitute the equation 4x+4z=0 into the equation 4x+3y+4z=1. Then,

1=4x+3y+4z = 3y + (4x+4z)= 3y+0.

From the expression above it is easy to obtain that y=1/3, and the intersection point is P(0;1/3;0).

B) To obtain the parallel vector to both planes we use the cross product of the normal vector of the planes.

$\left[\begin{array}{ccc}i&j&k\\4&3&4\\4&0&4\end{array}\right] = 12i-0j+12k$

As we want a unit vector, we must calculate the modulus of u:

$|u|=\sqrt{12^2+0^2+12^2} = \sqrt{2\cdot 12^2}=12\sqrt{2}$ .

Thus, the wanted vector is $\frac{u}{12\sqrt{2}}$ . Therefore,

$u = \frac{1}{\sqrt{2}}i-\frac{1}{\sqrt{2}}k = \frac{\sqrt{2}}{2}i-\frac{\sqrt{2}}{2}k$ .

C) In order to obtain the vector equation of the intersection line of both planes, we just need to put together the above results.

$r = \frac{1}{3}j +\lambda \left( \frac{\sqrt{2}}{2}i- \frac{\sqrt{2}}{2}k \right)$

where $\lambda$ is a real number.

8 0

4 years ago