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4 years ago

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Explain why the probability mass function p(x = 1000) = 0.1, p(x = 1500) = 0.2, p(x = 2000) = 0.3, p(x = 2500) = 0.3, p(x = 3000

) = 0.1 is absurd as a distribution for the number of phone calls to a help-desk call center during a day.

1 answer:

OlgaM077 [116]4 years ago

5 0

Chances are a call center will rarely receive *exactly* 1000 calls, or 1500, or 2000, ...

A more likely choice would be, for instance, $\mathbb P(X\le1000)=0.1$ , $\mathbb P(1000$ , ...

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CAN SOMEONE HELP ME PLS<br> 15 POINTS!!!!

nasty-shy [4]

20 is no because its bigger than 15

11 yes because its less than 15

16 is no because its more than 15

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3 years ago

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Suppose a, b denotes of the quadratic polynomial x² + 20x - 2022 & c, d are roots of x² - 20x + 2022 then the value of ac(a

Alja [10]

<h3><u>Correct Question :- </u></h3>

$\sf\:a,b \: are \: the \: roots \: of \: {x}^{2} + 20x - 2020 = 0 \: and \: \\ \sf \: c,d \: are \: the \: roots \: of \: {x}^{2} - 20x + 2020 = 0 \: then \:$

$\sf \: ac(a - c) + ad(a - d) + bc(b - c) + bd(b - d) =$

(a) 0

(b) 8000

(c) 8080

(d) 16000

$\large\underline{\sf{Solution-}}$

Given that

$\red{\rm :\longmapsto\:a,b \: are \: the \: roots \: of \: {x}^{2} + 20x - 2020 = 0}$

We know

$\boxed{\red{\sf Product\ of\ the\ zeroes=\frac{Constant}{coefficient\ of\ x^{2}}}}$

$\rm \implies\:ab = \dfrac{ - 2020}{1} = - 2020$

And

$\boxed{\red{\sf Sum\ of\ the\ zeroes=\frac{-coefficient\ of\ x}{coefficient\ of\ x^{2}}}}$

$\rm \implies\:a + b = - \dfrac{20}{1} = - 20$

Also, given that

$\red{\rm :\longmapsto\:c,d \: are \: the \: roots \: of \: {x}^{2} - 20x + 2020 = 0}$

$\rm \implies\:c + d = - \dfrac{( - 20)}{1} = 20$

and

$\rm \implies\:cd = \dfrac{2020}{1} = 2020$

Now, Consider

$\sf \: ac(a - c) + ad(a - d) + bc(b - c) + bd(b - d)$

$\sf \: = {ca}^{2} - {ac}^{2} + {da}^{2} - {ad}^{2} + {cb}^{2} - {bc}^{2} + {db}^{2} - {bd}^{2}$

$\sf \: = {a}^{2}(c + d) + {b}^{2}(c + d) - {c}^{2}(a + b) - {d}^{2}(a + b)$

$\sf \: = (c + d)( {a}^{2} + {b}^{2}) - (a + b)( {c}^{2} + {d}^{2})$

$\sf \: = 20( {a}^{2} + {b}^{2}) + 20( {c}^{2} + {d}^{2})$

$\sf \: = 20\bigg[ {a}^{2} + {b}^{2} + {c}^{2} + {d}^{2}\bigg]$

We know,

$\boxed{\tt{ { \alpha }^{2} + { \beta }^{2} = {( \alpha + \beta) }^{2} - 2 \alpha \beta \: }}$

So, using this, we get

$\sf \: = 20\bigg[ {(a + b)}^{2} - 2ab + {(c + d)}^{2} - 2cd\bigg]$

$\sf \: = 20\bigg[ {( - 20)}^{2} + 2(2020) + {(20)}^{2} - 2(2020)\bigg]$

$\sf \: = 20\bigg[ 400 + 400\bigg]$

$\sf \: = 20\bigg[ 800\bigg]$

$\sf \: = 16000$

Hence,

$\boxed{\tt{ \sf \: ac(a - c) + ad(a - d) + bc(b - c) + bd(b - d) = 16000}}$

<em>So, option (d) is correct.</em>

4 0

3 years ago

Juan wants to change the shape of his vegetable garden from a square to a rectangle, but keep the same area so he can grow the s

Naddika [18.5K]

For the square, the area will be 4x4, which will equal 16 sq ft. Since Juan is wanting to turn it to a rectangle, he will have to use the equation 8x2.

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4 years ago

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Using the data in the table, which statement is true?

horsena [70]

Answer: Choice C. mean > median

================================================

Explanation:

Multiply each measure with their corresponding frequency.

8*1 = 8
10*3 = 30
14*2 = 28

Add up those products: 8+30+28 = 66

Then divide by the total frequency n = 1+3+2 = 6 to get 66/6 = 11 as the mean.

mean = 11

----------------

Since we have n = 6 values in this list, this means the median is between slot n/2 = 6/2 = 3 and slot 4.

Note how that places us in the middle row because 1+3 = 4 encapsulates both of those slots mentioned. So the median is 10.

Or you could list out the values in roster notation {8, 10, 10, 10, 14, 14} to see that {10,10} occupy the middle most slots. So the median is (10+10)/2 = 20/2 = 10.

median = 10

-----------------

The mode is simply the most frequent value. The table shows that mode = 10 since it occurs 3 times, compared to 8 showing up 1 time and 14 showing up twice.

-----------------

We have the following summary

mean = 11
median = 10
mode = 10

With that in mind, let's go through the answer choices.

We can see that mean < mode is false, since it should be mean > median, so cross choice A off the list.
mean = median is also false, so choice B is crossed off as well.
mean > median is true since 11 > 10 is true. Choice C is the answer. Note how this being true directly contradicts choice B, which is another reason to see why choice B is false.
median > mode is false because 10 > 10 is false. It should be median = mode. Choice D is crossed off the list.

4 0

3 years ago

Need help quick please

valina [46]

Answer:

Disagree

Step-by-step explanation:

Remember rotating 90 degrees means (y,-x)

A= (1,2)

A'= (2,-1)

So it is disagreed.

Hope this help :)

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3 years ago

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