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Ad libitum [116K]

2 years ago

8

The monthly utility bills in a city at e normally distributed, with a mean $100 and a standard deviation of $13. find the probab

ility that a randomly selected utility bill is (a) a less than $70, (b) between $85 and $120, and(c) more than $140.

1 answer:

dmitriy555 [2]2 years ago

5 0

Answer:

how's your day

Step-by-step explanation:

how's your day

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natka813 [3]

Answer:

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Step-by-step explanation:

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2 years ago

Please help anyone and thank you

snow_lady [41]

Answer and Step-by-step explanation:

The two statements that are true are statement 1 and statement 4:

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2 years ago

The base of a triangle is nine centimeters longer than the perpendicular height. If the area of the triangle is 180 square centi

Rom4ik [11]

Answer:

<em>The base is 24 cm long.</em>

Step-by-step explanation:

<u>Equations</u>

Let's call

b= base of the triangle

h=height of the triangle

The base is 9 cm longer than the height, thus:

b = h + 9

The area of the triangle is:

$\displaystyle A=\frac{bh}{2}$

$\displaystyle A=\frac{(h+9)h}{2}$

And its value is 180:

$\displaystyle \frac{(h+9)h}{2}=180$

Multiplying by 2:

$(h+9)h=360$

Operating:

$h^2+9h-360=0$

Factoring:

$(h-15)(h+24)=0$

The only valid positive solution is:

h = 15 cm

And b = h + 9 = 24

b = 24 cm

The base is 24 cm long.

7 0

2 years ago

Please help me please

Anastaziya [24]

Answer:

the answer is A ...........

8 0

2 years ago

A manager wishes to determine the relationship between the number of miles (in hundreds of miles) the manager's sales representa

Aleksandr [31]

Answer:

$y=3.529 x +37.91$

We can predict the sales representative travelled 8 miles replacing x =8 and we got:

$y(8) = 3.529*8 + 37.91= 66.142$

And we can predict the sales representative travelled 11 miles replacing x =11 and we got:

$y(11) = 3.529*11 + 37.91= 76.729$

Step-by-step explanation:

For this case we have the following data:

Miles Traveled x: 2,3,10,7,8,15,3,1,11

Sales y :31,33,78,62,65,61,48,55,120

For this case we need to calculate the slope with the following formula:

$m=\frac{S_{xy}}{S_{xx}}$

Where:

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}$

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}$

So we can find the sums like this:

$\sum_{i=1}^n x_i =60$

$\sum_{i=1}^n y_i =553$

$\sum_{i=1}^n x^2_i =582$

$\sum_{i=1}^n y^2_i =39653$

$\sum_{i=1}^n x_i y_i =4329$

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=582-\frac{60^2}{9}=182$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}=4329-\frac{60*553}{9}=642.33$

And the slope would be:

$m=\frac{642.33}{182}=3.529$

Nowe we can find the means for x and y like this:

$\bar x= \frac{\sum x_i}{n}=\frac{60}{9}=6.67$

$\bar y= \frac{\sum y_i}{n}=\frac{553}{9}=61.44$

And we can find the intercept using this:

$b=\bar y -m \bar x=61.44-(3.529*6.67)=37.91$

So the line would be given by:

$y=3.529 x +37.91$

We can predict the sales representative travelled 8 miles replacing x =8 and we got:

$y(8) = 3.529*8 + 37.91= 66.142$

And we can predict the sales representative travelled 11 miles replacing x =11 and we got:

$y(11) = 3.529*11 + 37.91= 76.729$

4 0

3 years ago