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3 years ago

Pls if anyone knows the answer with work included/steps that will be greatly appreciated :)

Mathematics

2 answers:

Leni [432]3 years ago

8 0

Step-by-step explanation:

3. The length of the rectangle is 3x and width is x+5

Now,

Area of rectangle=l×b

=3x(x+5)

=3x^2+15x(option d.)

4. 2/3x-4=20

2x/3=20+4

2x/3=24

2x=24×3

2x=72

x=72/2

x=36(option d.)

irina [24]3 years ago

6 0

Answer:

3. 3x^2 + 15x

4. x=36

Step-by-step explanation:

The area of a rectangle is

A = l*w

A = (3x)*(x+5)

Distribute

3x^2 + 15x

2/3x - 4 = 20

Add 4 to each side

2/3x -4+4 = 20+4

2/3x = 24

Multiply each side by 3/2

2/3*3/2 =24*3/2

x = 12*3

x=36

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32÷891 using long division

valentinak56 [21]

It would be 0.03591470258136924803591470258136924803

5 0

3 years ago

Read 2 more answers

In a random sample of 150 customers of a high-speed Internetprovider, 63 said that their service had been interrupted one ormore

erastovalidia [21]

Answer:

a) The 95% confidence interval would be given by (0.341;0.499)

b) The 99% confidence interval would be given by (0.316;0.524)

c) n=335

d)n=649

Step-by-step explanation:

1) Notation and definitions

$X_{IS}=63$ number of high speed internet users that had been interrupted one or more times in the past month.

$n=150$ random sample taken

$\hat p_{IS}=\frac{63}{150}=0.42$ estimated proportion of high speed internet users that had been interrupted one or more times in the past month.

$p_{IS}$ true population proportion of high speed internet users that had been interrupted one or more times in the past month.

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

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

1) Part a

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:

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

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

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

If we replace the values obtained we got:

$0.42 - 1.96\sqrt{\frac{0.42(1-0.42)}{150}}=0.341$

$0.42 + 1.96\sqrt{\frac{0.42(1-0.42)}{150}}=0.499$

The 95% confidence interval would be given by (0.341;0.499)

2) Part b

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 99% of confidence, our significance level would be given by $\alpha=1-0.99=0.01$ and $\alpha/2 =0.005$ . And the critical value would be given by:

$t_{\alpha/2}=-2.58, t_{1-\alpha/2}=2.58$

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

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

If we replace the values obtained we got:

$0.42 - 2.58\sqrt{\frac{0.42(1-0.42)}{150}}=0.316$

$0.42 + 2.58\sqrt{\frac{0.42(1-0.42)}{150}}=0.524$

The 99% confidence interval would be given by (0.316;0.524)

3) Part c

The margin of error for the proportion interval is given by this formula:

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

And on this case we have that $ME =\pm 0.05$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

And replacing into equation (b) the values from part a we got:

$n=\frac{0.42(1-0.42)}{(\frac{0.05}{1.96})^2}=374.32$

And rounded up we have that n=335

4) Part d

The margin of error for the proportion interval is given by this formula:

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

And on this case we have that $ME =\pm 0.05$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

And replacing into equation (b) the values from part a we got:

$n=\frac{0.42(1-0.42)}{(\frac{0.05}{2.58})^2}=648.599$

And rounded up we have that n=649

5 0

3 years ago

If a non zero number is divided by a zero then what is the notation to denote it

enot [183]

Answer:

0 Divided by a Number 0a=0 Dividing 0 by any number gives us a zero. Zero will never change when multiplying or dividing any number by it.

if i helped please give brainliest and a thanks !!

3 0

3 years ago

Which of the following statements must be true based on the diagram below? Select

pentagon [3]

The question is an illustration of equivalent ratios and similar triangles.

The true option is: $\frac{WU}{WV} = \frac{UR}{VS}$

From the diagram, we have:

$WU = UR$ ---- This is so because both lines are marked once

Also, we have:

$WV = VS$ ---- This is so because both lines are marked twice

Divide both equations

$\frac{WU}{WV} = \frac{UR}{VS}$

Hence, the true option is: $\frac{WU}{WV} = \frac{UR}{VS}$

Read more about similar triangles at:

brainly.com/question/19739157

8 0

3 years ago

tres hermanos danvueltas circuito en bicicleta. el mayor tarda 18 en dar Una vuelta el del medio 24 minutos yel menos 36 minutos

hodyreva [135]

Tienes que hallar el mínimo común múltiplo de las 3 cantidades.

18= 2×3²
24= 2³×3
36= 2²×3²

mcm(18,24,36) = 2³×3²=8×9= 72

Eso quier decir que si partieron a la misma hora se encontraran de nuevo en el punto de partida 72 minutos después de la salida.

Las vueltas que habrán realizado será el resultado de dividir 72 entre el tiempo que tardan en dar una vuelta

Mayor: = 4

Mediano: = 3

Pequeño: = 2

Soluciónes:

se vuelven a encontrar a los 72 min de la salida
El mayor dió 4 vueltas, el mediano 3 y el pequeño 2

6 0

3 years ago