Use Gauss's approach to find the following sums (do not use formulas). a. 1+2+3+4+...+98

Question 7(Multiple Choice Worth 75 points) Which of the following is true of all minerals? Made of many different elements Come

algol [13]

The true statement is that minerals come from the ground as crystals. Hope this helps!

4 0

3 years ago

Which fraction is not equivalent to 9/12

Usimov [2.4K]

Answer: 1/2

1/2 = 50%

9/12 = 75%

6 0

3 years ago

Read 2 more answers

Is the equation true, false, or open? Explain. -9a + 3 = -9a + 3* 5

Sholpan [36]

Answer:

the answer is false because 3 is multiplied with 5 on the right side

Then, when substitute any number , there remain difference

8 0

3 years ago

An automobile dealer wants to see if there is a relationship between monthly sales and the interest rate. A random sample of 4 m

SVETLANKA909090 [29]

Answer:

a) $y=-6.254 x +75.064$

b) r =-0.932

The % of variation is given by the determination coefficient given by $r^2$ and on this case $-0.932^2 =0.8687$ , so then the % of variation explained by the linear model is 86.87%.

Step-by-step explanation:

Assuming the following dataset:

Monthly Sales (Y) Interest Rate (X)

22 9.2

20 7.6

10 10.4

45 5.3

Part a

And we want a linear model on this way y=mx+b, where m represent the slope and b the intercept. In order to find the slope we have this formula:

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

Where:

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

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

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=278.65-\frac{32.5^2}{4}=14.5875$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i){n}}=696.9-\frac{32.5*97}{4}=-91.225$

And the slope would be:

$m=\frac{-91.225}{14.5875}=-6.254$

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

$\bar x= \frac{\sum x_i}{n}=\frac{32.5}{4}=8.125$

$\bar y= \frac{\sum y_i}{n}=\frac{97}{4}=24.25$

And we can find the intercept using this:

$b=\bar y -m \bar x=24.25-(-6.254*8.125)=75.064$

So the line would be given by:

$y=-6.254 x +75.064$

Part b

For this case we need to calculate the correlation coefficient given by:

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

$r=\frac{4(696.9)-(32.5)(97)}{\sqrt{[4(278.65) -(32.5)^2][4(3009) -(97)^2]}}=-0.937$

So then the correlation coefficient would be r =-0.932

The % of variation is given by the determination coefficient given by $r^2$ and on this case $-0.932^2 =0.8687$ , so then the % of variation explained by the linear model is 86.87%.

6 0

3 years ago

Topic: Absolute Value Equations and Inequalities

jolli1 [7]

The values of x are -22 and -2 and there are not extraneous solutions

<h3>How to solve the equation?</h3>

The equation is given as:

2|x + 7|= x - 8

Expand the absolute bracket

|2x + 14|= x - 8

Remove the absolute bracket

2x + 14 = x - 8 and 2x + 14 = -x + 8

Evaluate the like terms

x = -22 and 3x = -6

This gives

x = -22 and x = -2

Hence, the values of x are -22 and -2 and there are not extraneous solutions

Read more about absolute value expressions at:

brainly.com/question/24368848

#SPJ1

4 0

2 years ago

Use​ Gauss's approach to find the following sums​ (do not use​ formulas). a. 1+2+3+4+...+98

Use Gauss's approach to find the following sums (do not use formulas). a. 1+2+3+4+...+98