Which expression is a factor of 21x2 + 13x − 20?

Which two numbers on the number line have an absolute value of 2.75?

AysviL [449]

Answer:

2.75 and -2.75

Step-by-step explanation:

The absolute value of 2.75 is 2.75 and the absolute value of -2.75 is 2.75

3 0

2 years ago

a travel agency charges $64 for each bus ticket and $82 for each train ticket. how much does it cost to buy 3 bus tickets and 4

jekas [21]

520 dollars for 4 train tickets and 3 bus tickets.

6 0

3 years ago

If a pound of coffee costs $6, how many ounces can be bought for $3

saveliy_v [14]

8

Because 16 ounces is a pound half of 16 is 8, 8 ounces is half a pound. :)

8 0

3 years ago

Read 2 more answers

An office is divided into 12 cubicles. How many of the cubicles are carpeted if 1/3 of the cubicles are carpeted

11Alexandr11 [23.1K]

12÷3=4
cause 1/3 in this situation is 3 cause 12÷4 is 3

5 0

3 years ago

The least-squares regression model y =−3.4+5.2x and correlation coefficient r=−0.66 were calculated for a set of bivariate data

Makovka662 [10]

Answer:

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

For this case the value of r = -0.66

Now we can calculate the determination coeffcient:

$r^2 = (-0.66)^2 = 0.4356$

And then we can conclude that 43.56% of the variation in y can be explained by the explanatory variable

And then 100-43.56 = 56.44 % of the variation in y that cannot be explained by the explanatory variable

Step-by-step explanation:

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

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

Where:

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

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

$\bar x= \frac{\sum x_i}{n}$

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

And we can find the intercept using this:

$b=\bar y -m \bar x$

And the model obtained for this case is:

$y = -3.4 +5.2 x$

The correlation coefficient is a "statistical measure that calculates the strength of the relationship between the relative movements of two variables". It's denoted by r and its always between -1 and 1.

And in order to calculate the correlation coefficient we can use this formula:

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

For this case the value of r = -0.66

Now we can calculate the determination coeffcient:

$r^2 = (-0.66)^2 = 0.4356$

And then we can conclude that 43.56% of the variation in y can be explained by the explanatory variable

And then 100-43.56 = 56.44 % of the variation in y that cannot be explained by the explanatory variable

8 0

3 years ago