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3 years ago

In how many minutes will a heart beat in 140 times?

Mathematics

2 answers:

matrenka [14]3 years ago

7 0

The answer is 5 minutes

s2008m [1.1K]3 years ago

5 0

The answer is about 3 minutes!

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Write each of the following expressions without using absolute value: |z−6|−|z−5|, if z<5

abruzzese [7]

Answer:

The answer is 1.

Step-by-step explanation:

Given the expression:

$|z-6|-|z-5|,\ if\ z$

To find:

The expression without absolute value.

Solution:

First of all, let us learn about the absolute value function:

$y = f(x) = |x| =\left \{ {{x\ if\ x>0} \atop {-x\ if\ x$

i.e. value is x if x is positive

value is -x if x is negative

Here the given expression contains two absolute value functions:

$|z-6|$ and $|z-5|$

Using the definition of absolute value function as per above definition.

$|z-5| =\left \{ {{(z-5)\ if\ z>5} \atop {-(z-5)\ if\ z$

$|z-6| =\left \{ {{(z-6)\ if\ z>6} \atop {-(z-6)\ if\ z$

Now, it is given that z < 5 that means z will also be lesser than 6 i.e. z < 6

So, given expression $|z-6|-|z-5|,\ if\ z$ will be equivalent to :

$-(z-6) - (-(z-5))\\\Rightarrow -z+6 +z-5 = \bold{1}$

So, the expression is equivalent to 1.

6 0

3 years ago

Assume you have noted the following prices for books and the number of pages that each book contains. Book Pages (x) Price (y) A

belka [17]

Answer:

a) $y=0.00991 x +1.042$

b) $r^2 = 0.7503^2 = 0.563$

c) $r=\frac{7(30095)-(4210)(49)}{\sqrt{[7(2595100) -(4210)^2][7(354) -(49)^2]}}=0.7503$

Step-by-step explanation:

Data given

x: 500, 700, 750, 590 , 540, 650, 480

y: 7.00, 7.50 , 9.00, 6.5, 7.50 , 7.0, 4.50

Part a

We want to create a linear model like this :

$y = mx +b$

Wehre

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

And:

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

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

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=2595100-\frac{4210^2}{7}=63085.714$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i){n}}=30095-\frac{4210*49}{7}=625$

And the slope would be:

$m=\frac{625}{63085.714}=0.00991$

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

$\bar x= \frac{\sum x_i}{n}=\frac{4210}{7}=601.429$

$\bar y= \frac{\sum y_i}{n}=\frac{49}{7}=7$

And we can find the intercept using this:

$b=\bar y -m \bar x=7-(0.00991*601.429)=1.042$

And the line would be:

$y=0.00991 x +1.042$

Part b

The correlation coefficient is given by:

$r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}$

For our case we have this:

n=7 $\sum x = 4210, \sum y = 49, \sum xy = 30095, \sum x^2 =2595100, \sum y^2 =354$

$r=\frac{7(30095)-(4210)(49)}{\sqrt{[7(2595100) -(4210)^2][7(354) -(49)^2]}}=0.7503$

The determination coefficient is given by:

$r^2 = 0.7503^2 = 0.563$

Part c

$r=\frac{7(30095)-(4210)(49)}{\sqrt{[7(2595100) -(4210)^2][7(354) -(49)^2]}}=0.7503$

4 0

3 years ago

An 8-quart jug of water costs $6.08. What is the price per cup?

padilas [110]

Answer:

$0.19 cents

Step-by-step explanation:

First, find how many cups are in 8 quarts.

1 quart is 4 cups, so to find the number of cups, multiply 8 by 4:

8(4)

= 32 cups

Then, to find the price per cup, divide the cost by the number of cups:

6.08/32

= 0.19

So, the price per cup is $0.19 cents

3 0

3 years ago

4. Compare using <> or = -5 O -9

tatiyna

Answer:

-9 <-5 <0

Step-by-step explanation:

hope it helps

for any question comment me❤❤

7 0

3 years ago

Some birds were flying and met a bird on their way. The bird greeted them; hello hundred! They said we are not hundred, we need

Alex_Xolod [135]

Answer:

I'm not certain but it sounds as though there would be 150 birds flying .

Step-by-step explanation:

The first bird says we are not hundred, they need half their group population plus the second birds group population. So if we are trying to get 100 from two groups the easiest numbers would be to add 50 and 50. So if we have the second groups whole population be 50 birds then the first group's whole population must be 100. The first bird said half of us so that means half of 100 which would be 50. If you add half of the first groups population, which is 50(100/2=50), plus the second groups whole population (50), you get 100 birds. Which means if you add the first groups total population(100) with the second groups total population(50) you get 150 total birds flying.

4 0

3 years ago