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2 years ago

Help please I will mark brainlest

Mathematics

2 answers:

Effectus [21]2 years ago

8 0

Answer:

they need brainliest :)

rodikova [14]2 years ago

7 0

Answer:

$5\sqrt{7}$

Step-by-step explanation:

$\frac{30\sqrt{14} }{6\sqrt{2} }$

Cancel out 6 in both numerator and denominator.

$\frac{5\sqrt{14} }{\sqrt{2} }$ Rationalize the denominator of $\frac{5\sqrt{14} }{\sqrt{2} }$ by multiplying the numerator and denominator by $\sqrt{2}$ .

$\frac{5\sqrt{14}\sqrt{2} }{(\sqrt{2})^{2} }$

The square of $\sqrt{2}$ is 2

Factor 14=2 × 7. Rewrite the square root of the product $\sqrt{2x7}$ as the product of square roots $\sqrt{2}\sqrt{7}$ .

$\frac{5\sqrt{2}\sqrt{7}\sqrt{2} }{2}$

Multiply $\sqrt{2}$ and $\sqrt{2}$ to get 2.

$\frac{5x2\sqrt{7} }{2}$

Cancel out 2 and 2.

$5\sqrt{7}$

Hope it helps and have a great day! =D

You might be interested in

4- A manufacturing process produces items whose weights are normally distributed. It is known that 22.57% of all the items produ

galben [10]

Answer:

$\\ \mu = 118\;grams\;and\;\sigma=30\;grams$

Step-by-step explanation:

We need to use z-scores and a standard normal table to find the values that corresponds to the probabilities given, and then to solve a system of equations to find $\\ \mu\;and\;\sigma$ .

<h3>First Case: items from 100 grams to the mean</h3>

For finding probabilities that corresponds to z-scores, we are going to use here a <u>Standard Normal Table </u><u><em>for cumulative probabilities from the mean </em></u><em>(Standard normal table. Cumulative from the mean (0 to Z), 2020, in Wikipedia) </em>that is, the "probability that a statistic is between 0 (the mean) and Z".

A value of a z-score for the probability P(100<x<mean) = 22.57% = 0.2257 corresponds to a value of z-score = 0.6, that is, the value is 0.6 standard deviations from the mean. Since this value is <em>below the mean</em> ("the items produced weigh between 100 grams up to the mean"), then the z-score is negative.

Then

$\\ z = -0.6\;and\;z = \frac{x-\mu}{\sigma}$

$\\ -0.6 = \frac{100-\mu}{\sigma}$ (1)

<h3>Second Case: items from the mean up to 190 grams</h3>

We can apply the same procedure as before. A value of a z-score for the probability P(mean<x<190) = 49.18% = 0.4918 corresponds to a value of z-score = 2.4, which is positive since it is after the mean.

Then

$\\ z =2.4\;and\; z = \frac{x-\mu}{\sigma}$

$\\ 2.4 = \frac{190-\mu}{\sigma}$ (2)

<h3>Solving a system of equations for values of the mean and standard deviation</h3>

Having equations (1) and (2), we can form a system of two equations and two unknowns values:

$\\ -0.6 = \frac{100-\mu}{\sigma}$ (1)

$\\ 2.4 = \frac{190-\mu}{\sigma}$ (2)

Rearranging these two equations:

$\\ -0.6*\sigma = 100-\mu$ (1)

$\\ 2.4*\sigma = 190-\mu$ (2)

To solve this system of equations, we can multiply (1) by -1, and them sum the two resulting equation:

$\\ 0.6*\sigma = -100+\mu$ (1)

$\\ 2.4*\sigma = 190-\mu$ (2)

Summing both equations, we obtain the following equation:

$\\ 3.0*\sigma = 90$

Then

$\\ \sigma = \frac{90}{3.0} = 30$

To find the value of the mean, we need to substitute the value obtained for the standard deviation in equation (2):

$\\ 2.4*30 = 190-\mu$ (2)

$\\ 2.4*30 - 190 = -\mu$

$\\ -2.4*30 + 190 = \mu$

$\\ \mu = 118$

7 0

2 years ago

Harry and Lisa Perry have agreed to pay for their granddaughter’s college education and need to know how much to set aside so an

Jobisdone [24]

Answer:

$117,836.49

Step-by-step explanation:

We can't make heads or tails of your table, so we have used a financial calculator to determine the multiplier is about 4.713. The calculator maintains more significant digits than that, so gives the value to the penny as ...

$117.836.49

_____

This value is about 4.71345951 × $25,000.

7 0

3 years ago

a slitter assembly contains 48 blades five blades are selected at random and evaluated each day for sharpness if any dull blade

son4ous [18]

Answer:

P(at least 1 dull blade)=0.7068

Step-by-step explanation:

I hope this helps.

This is what it's called dependent event probability, with the added condition that at least 1 out of 5 blades picked is dull, because from your selection of 5, you only need one defective to decide on replacing all.

So if you look at this from another perspective, you have only one event that makes it so you don't change the blades: that 5 out 5 blades picked are sharp. You also know that the probability of changing the blades plus the probability of not changing them is equal to 100%, because that involves all the events possible.

P(at least 1 dull blade out of 5)+Probability(no dull blades out of 5)=1

P(at least 1 dull blade)=1-P(no dull blades)

But the event of picking one blade is dependent of the previous picking, meaning there is no chance of picking the same blade twice.

So you have 38/48 on getting a sharp one on your first pick, then 37/47 (since you remove 1 sharp from the possibilities, and 1 from the whole lot), and so on.

Also since are consecutive events, you need to multiply the events.

The probability that the assembly is replaced the first day is:

P(at least 1 dull blade)=1-P(no dull blades)

$P(at least 1 dull blade)=1-(\frac{38}{48}* \frac{37}{47} *\frac{36}{46}*\frac{35}{45}*\frac{34}{44})$

$P(at least 1 dull blade)=1-0.2931$

P(at least 1 dull blade)=0.7068

5 0

3 years ago

In the context of correlational research, if there is no relationship between two variables, what is the correlation coefficient

mel-nik [20]

Answer:

The Correlation coefficient is 0

Step-by-step explanation:

3 0

2 years ago

Please help meeee !!

katrin [286]

Answer:

The answer is B

3 0

3 years ago