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3 years ago

12

A researcher wants to examine the effect of caffeine on sleep. She splits participants into two groups. The first group drinks c

affeinated-coffee at 8pm and the second group drinks decaf-coffee at 8pm. The researcher records what time participants fall asleep. What is the independent variable

1 answer:

Oduvanchick [21]3 years ago

8 0

Answer:

Type of coffee

Step-by-step explanation:

First, that is, it is the independent variable.

It is the variable that does not depend on another value or other circumstance, it is the variable that generally would be the options to choose from and depending on what is chosen, different results are obtained.

In this case, the variable that has this behavior is the type of coffee that will be taken, whether it is caffeinated or decaffeinated coffee.

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¿Cuál expresión equivale a 12 dividido entre raíz de 3

Ira Lisetskai [31]

Answer:

4

Step-by-step explanation:

12/3=4

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2 years ago

A family eats at a restaurant. The bill is $56.75. They are pleased with service so they leave 22% tip. What is their total afte

nika2105 [10]

$69.24 is the correct answer because 56.75 multiplied by 1.22 is 69.24

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3 years ago

Find the slope of the line that passes through the pair of points

love history [14]

Answer:

$\frac{5,805}{2812}$

Step-by-step explanation:

To find the slope from two points you can use the following formula:

$m = \frac{y -y_{1} }{x -x_{1} }$

Now substitute the two sets of points $(\frac{7}{20}, \frac{5}{19} ) and (\frac{5}{9}, \frac{11}{16})$

Substitute the values like this:

$y = \frac{5}{19}, y_{1} = \frac{11}{16}, x = \frac{7}{20}$ and $x_{1} =\frac{5}{9}$

Now you will need to simplify the following expression:

$m = \frac{\frac{5}{19} -\frac{11}{16} }{\frac{7}{20}-\frac{5}{9} }$

Make sure that denominators are the same before substracting:

$m = \frac{\frac{-129}{304} }{\frac{-37}{180} }$

when you divide with a fractional number you only need to flip the second fraction over (find its reciprocal). Then just multiply:

$m = (\frac{-129}{304} })({\frac{-180}{37} } ) = \frac{5805}{2812}$

5 0

3 years ago

#5 Antonio and Abby had the same nimber of paperclips. After Antonio gave 30 paperclips to Abby, Abby had twice as many papercli

Kay [80]

Answer:

#5: 180 paperclips in total.

#6: 126 stamps in total.

#7: Elena should give Lucy 15 colored pencils.

Step-by-step explanation:

This explanation solves each question by setting a single unknown, $x$ .

<h3>#5</h3>

Let $x$ the initial number of paperclips of Antonio. That should also be the number of Abby's paperclips.

Initially:

Antonio: $x$ paperclips;
Abby: $x$ paperclips.

Antonio gives $30$ paperclips to Abby. After that,

Antonio: $(x - 30)$ paperclips;
Abby: $x + 30$ paperclips.

Abby now possess twice as many paperclips as Antonio does. In other words,

$2(x - 30) = x + 30$ .

By the distributive property:

$2x - 60 = x + 30$ .

Substract $x - 60$ from both sides

$x = 30 - (-60) = 90$ .

Both Antonio and Abby initially possess 90 paperclips. That's 180 in total.

<h3>#6</h3>

Similarly, let $x$ be the number of Emily's stamps. That should be the same as the number of Jasmine's stamps.

Initially:

Emily: $x$ stamps;
Jasmine: $x$ stamps.

After Emily gives $42$ stamps to Jasmine:

Emily: $x-42$ stamps;
Jasmine: $x+42$ stamps.

Jasmine now possesses twice as many stamps as Emily does. In other words,

$2(x-42) = x+42$ .

$x = 42 + 2\times 42 = 126$ .

Jasmine used to possess 126 stamps. Now she possesses $126 + 42 = 168$ stamps after receiving $42$ stamps from Emily.

<h3>#7</h3>

Let the number of pencils that Elena needs to give to Lucy be $x$ .

Initially:

Elena: 60 pencils;
Lucy: 26 pencils.

After Elena gives $x$ pencils to Lucy:

Elena: $60 - x$ pencils;
Lucy: $26 + x$ pencils.

Elena should now possess four more pencils than Lucy does. In other words,

$\underbrace{60 - x}_{\text{Elena's}} = \underbrace{(26 + x)}_{\text{Lucy's}} +4$ .

$2x = 30$ .

$x = 15$ .

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3 years ago

Suppose that a country of 72 million people about 3600 die from drowning each year. What is the percent chance that a person wil

Sloan [31]

Your answer is 0.003%

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3 years ago