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3 years ago

Which of the following numbers is shown plotted on the number line ? I need help!

Mathematics

2 answers:

Bingel [31]3 years ago

8 0

Answer:

Last One -3 3/8

Step-by-step explanation:

it is negative and there are 3 lines so automatically 3

kykrilka [37]3 years ago

5 0

The number is -3 3/8

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Which impression is equivalent to - 3/4 / -( 8 / 12)

Makovka662 [10]

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3 years ago

13 x (-3)-7 x (-3) what is the answer to this problem x means multiplication

iren2701 [21]

138 should be your answer.

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4 years ago

Read 2 more answers

The mean number of words per minute (WPM) read by sixth graders is 8888 with a standard deviation of 1414 WPM. If 137137 sixth g

Bingel [31]

Noticing that there is a pattern of repetition in the question (the numbers are repeated twice), we are assuming that the mean number of words per minute is 88, the standard deviation is of 14 WPM, as well as the number of sixth graders is 137, and that there is a need to estimate the probability that the sample mean would be greater than 89.87.

Answer:

"The probability that the sample mean would be greater than 89.87 WPM" is about $\\ P(z>1.56) = 0.0594$ .

Step-by-step explanation:

This is a problem of the distribution of sample means. Roughly speaking, we have the probability distribution of samples obtained from the same population. Each sample mean is an estimation of the population mean, and we know that this distribution behaves normally for samples sizes equal or greater than 30 $\\ n \geq 30$ . Mathematically

$\\ \overline{X} \sim N(\mu, \frac{\sigma}{\sqrt{n}})$ [1]

In words, the latter distribution has a mean that equals the population mean, and a standard deviation that also equals the population standard deviation divided by the square root of the sample size.

Moreover, we know that the variable Z follows a normal standard distribution, i.e., a normal distribution that has a population mean $\\ \mu = 0$ and a population standard deviation $\\ \sigma = 1$ .

$\\ Z = \frac{\overline{X} - \mu}{\frac{\sigma}{\sqrt{n}}}$ [2]

From the question, we know that

The population mean is $\\ \mu = 88$ WPM
The population standard deviation is $\\ \sigma = 14$ WPM

We also know the size of the sample for this case: $\\ n = 137$ sixth graders.

We need to estimate the probability that a sample mean being greater than $\\ \overline{X} = 89.87$ WPM in the distribution of sample means. We can use the formula [2] to find this question.

The probability that the sample mean would be greater than 89.87 WPM

$\\ Z = \frac{\overline{X} - \mu}{\frac{\sigma}{\sqrt{n}}}$

$\\ Z = \frac{89.87 - 88}{\frac{14}{\sqrt{137}}}$

$\\ Z = \frac{1.87}{\frac{14}{\sqrt{137}}}$

$\\ Z = 1.5634 \approx 1.56$

This is a standardized value and it tells us that the sample with mean 89.87 is 1.56 standard deviations above the mean of the sampling distribution.

We can consult the probability of P(z<1.56) in any cumulative standard normal table available in Statistics books or on the Internet. Of course, this probability is the same that $\\ P(\overline{X} < 89.87)$ . Then

$\\ P(z$

However, we are looking for P(z>1.56), which is the complement probability of the previous probability. Therefore

$\\ P(z>1.56) = 1 - P(z$

$\\ P(z>1.56) = P(\overline{X}>89.87) = 0.0594$

Thus, "The probability that the sample mean would be greater than 89.87 WPM" is about $\\ P(z>1.56) = 0.0594$ .

5 0

3 years ago

What is the perimeter of parallelogram HIJK? Round to the nearest hundredth.

bixtya [17]

Answer:

Perimeter of the parallelogram = 26.64 units

Step-by-step explanation:

The perimeter of parallelogram = 2(a + b)

Here a = KJ = 7 units.

b = HK

We need to find the HK using the distance formula.

Distance formula = $\sqrt{(x2 - x1)^2 + (y2 - y1)^2}$

H = (-4, 3) and k = (-2, -3)

Now plug in x1 = -4, y1 =3, x2 = -2, y2 = -3 in the distance formula

HK = $\sqrt{(-2 -(-4))^2 + (-3 - 3)^2}$

= $\sqrt{(-2 +4)^2 + (-6)^2}$

= $\sqrt{4 + 36}$

= $\sqrt{40}$

HK = b = 6.32 units

Now plug in a = 7 and b = 6.32 in the perimeter formula, we get

Perimeter = 2(7 + 6.32)

= 2(13.32)

= 26.64 units

Thank you.

6 0

3 years ago

What's the volume? I honestly just need the formula.

Arturiano [62]

Answer:

$v=364.5\ m^3$

Step-by-step explanation:

Volume Of A Regular Solid

When a solid has a constant cross-section, the volume can be found by multiplying the area of the base by the height. The area of a trapezium is

$\displaystyle A_t=\frac{b_1+b_2}{2}h$

where $b_1$ and $b_2$ are the lengths of the parallel sides and h the distance between them.

The figure shows a solid with a trapezoid as the constant cross-section and a height x. The volume of the solid is

$\displaystyle v=A_t\ x$

$\displaystyle v=\frac{b_1+b_2}{2}\ h\ x$

The image doesn't explicitly say if the length of 4.5 is the height of the trapezium or the length of that side. We'll assume the first, so our data is:

$\displaystyle b_1=7m,\ b_2=11m,\ h=4.5m,\ x=9m$

We now compute the volume

$\displaystyle v=\frac{7+11}{2}.(4.5)(9)=364.5$

$\boxed{\displaystyle v=364.5\ m^3}$

8 0

3 years ago