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3 years ago

What is -2.3 - (4.5 - 3 1/2)?

Mathematics

2 answers:

Gemiola [76]3 years ago

4 0

-2.3 - (4.5 - 3 $\frac{1}{2}$ ) = -3.3

wolverine [178]3 years ago

4 0

Answer:

3.3

Step-by-step explanation:

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The yoga instructor earns$25 per class and $10 per student that shows up. They want to earn more than $385 teaching 6 classes th

Sedaia [141]

ANSWER: 24 people

All you have to do is multiply 25 and 6 to get 150. Then minus 150 from 385 to get 235. Then divide 235 by 10 to get 23.5, since you can not have half a person the answer is to round up to 24.

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2 years ago

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Billy likes to go cycling.

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3 years ago

Write and equati9n of a l8ne that passes through (1,-2) and is perpendicular to -4x+7y=21

yarga [219]

Given:

A line passes through (1,-2) and is perpendicular to $-4x+7y=21$ .

To find:

The equation of that line.

Solution:

We have, equation of perpendicular line.

$-4x+7y=21$

Slope of this line is

$m_1=-\dfrac{\text{Coefficient of x}}{\text{Coefficient of y}}$

$m_1=-\dfrac{-4}{7}$

$m_1=\dfrac{4}{7}$

Product of slope of two perpendicular lines is -1.

$m_1\times m_2=-1$

$\dfrac{4}{7}\times m_2=-1$

$m_2=-\dfrac{7}{4}$

Now, slope of required line is $-\dfrac{7}{4}$ and it passes through (1,-2). So, the equation of line is

$y-y_1=m(x-x_1)$

where, m is slope.

$y-(-2)=-\dfrac{7}{4}(x-1)$

$4(y+2)=-7(x-1)$

$4y+8=-7x+7$

$4y+7x=7-8$

$7x+4y=-1$

Therefore, the equation of required line is $7x+4y=-1$ .

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3 years ago

A sample of 13 sheets of cardstock is randomly selected and the following thicknesses are measured in millimeters. Give a point

valina [46]

<h3>Answer: 0.061</h3>

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

Explanation:

Add up the values to get

1.96+1.81+1.97+1.83+1.87+1.84+1.85+1.94+1.96+1.81+1.86+1.95+1.89= 24.54

Then divide over 13 (the number of values) to get 24.54/13 = 1.8876923 which is approximate.

So the mean is approximately 1.8876923

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

Now make a spreadsheet as shown below

We have the first column as the x values, which are the original numbers your teacher provided. The second column is of the form (x-M)^2, where M is the mean we computed earlier. We subtract off the mean and square the result.

After we compute that column of (x-M)^2 values, we add them up to get what is shown in the highlighted yellow cell at the bottom of the column.

That sum is approximately 0.04403076924

Next, we divide that over n-1 = 13-1 = 12

0.04403076924 /12 = 0.00366923077

That is the sample variance. Apply the square root to this to get the sample standard deviation. This is the point estimate of the population standard deviation. As the name implies, it works for samples that estimate population parameters.

sqrt(0.00366923077) = 0.06057417576822

This rounds to 0.061 which is the final answer.