Ask question

Ask question

All categories

4 years ago

7

How many planes appear in this figure? Name three points that are collinear. Are points a, b, c, and d coplanar? Explain. At wha

t does and ca interest db

1 answer:

xxTIMURxx [149]4 years ago

3 0

D, B, and A are collinear. Yes they are coplanar because they all lay on the same plane. And I don’t understand the last question

You might be interested in

Two athletic directors purchased tennis balls and baseballs at the same store. The first athletic director bought 5 tennis balls

BartSMP [9]

This question can be solved using 2 equations since there are 2 unknowns. First, let x = price of the tennis ball and y = price of the baseball. The resulting equations are: (1) 5x +3y = 23.75 and (2) 2x + 7y = 31.25. Solving the 2 equations simultaneously, you get, x = 2.5 and y = 3.75. The price of the baseball is then $3.75.

3 0

3 years ago

When engaging in weight control (fitness/fat burning) types of exercise, a person is expected to attain about 60% of their maxim

valkas [14]

Answer:

- There is enough evidence to support the claim that the heart rate level lower than 120 bpm (P-value=0.002).

- The 95% confidence interval for the population mean weight control heart rate of 20-year-olds is (98.07, 115.93).

Step-by-step explanation:

This is a hypothesis test for the population mean.

The claim is that the heart rate level lower than 120 bpm

Then, the null and alternative hypothesis are:

$H_0: \mu=120\\\\H_a:\mu< 120$

The significance level is 0.05.

The sample has a size n=100.

The sample mean is M=107.

As the standard deviation of the population is not known, we estimate it with the sample standard deviation, that has a value of s=45.

The estimated standard error of the mean is computed using the formula:

$s_M=\dfrac{s}{\sqrt{n}}=\dfrac{45}{\sqrt{100}}=4.5$

Then, we can calculate the t-statistic as:

$t=\dfrac{M-\mu}{s/\sqrt{n}}=\dfrac{107-120}{4.5}=\dfrac{-13}{4.5}=-2.889$

The degrees of freedom for this sample size are:

$df=n-1=100-1=99$

This test is a left-tailed test, with 99 degrees of freedom and t=-2.889, so the P-value for this test is calculated as (using a t-table):

$P-value=P(t$

As the P-value (0.002) is smaller than the significance level (0.05), the effect is significant.

The null hypothesis is rejected.

There is enough evidence to support the claim that the heart rate level lower than 120 bpm .

<u>Confidence interval:</u>

We have to calculate a 95% confidence interval for the mean.

The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.

The sample mean is M=107.

The sample size is N=100.

When σ is not known, s divided by the square root of N is used as an estimate of σM:

$s_M=\dfrac{s}{\sqrt{N}}=\dfrac{45}{\sqrt{100}}=\dfrac{45}{10}=4.5$

The t-value for a 95% confidence interval is t=1.984.

The margin of error (MOE) can be calculated as:

$MOE=t\cdot s_M=1.984 \cdot 4.5=8.929$

Then, the lower and upper bounds of the confidence interval are:

$LL=M-t \cdot s_M = 107-8.929=98.07\\\\UL=M+t \cdot s_M = 107+8.929=115.93$

The 95% confidence interval for the population mean weight control heart rate of 20-year-olds is (98.07, 115.93).

7 0

4 years ago

5x to the power of 2 + 2x +12+13x

pochemuha

Answer:

I believe the answer is

5x^2+15x+12.

5 0

3 years ago

Mr. Dufensmirtz is creating this year's final exam for his Precalculus students. Last

Sindrei [870]

Answer:

Hope it helps dear.Please let me know

6 0

3 years ago

Quadrilateral KLMN has vertices of K(-4,-1), L(-1,-1) M(-2,-5) and N(-4,-4) Find the length of MN

Olenka [21]

Answer:

The length of MN is $\sqrt{5}$ units.

Step-by-step explanation:

The given Quadrilateral KLMN has vertices at K(-4,-1), L(-1,-1) M(-2,-5) and N(-4,-4).

We use the distance formula to find the length of MN.

$|MN|=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$

We plug in the values to get

$|MN|=\sqrt{(-4--2)^2+(-4--5)^2}$

$|MN|=\sqrt{(-2)^2+(1)^2}$

$|MN|=\sqrt{4+1}$

$|MN|=\sqrt{5}$

The length of MN is $\sqrt{5}$ units.

3 0

4 years ago