225 to 270 I need help please help me

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

Please help

Vlada [557]

Answer is AAS hope this helps

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2 years ago

A kite with a 100 foot-long string is caught in a tree. When the full length of the string is stretched in a straight line to th

spayn [35]

Hyp=100,adj side=30

angle= $cos^{-1}(30/100)$

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3 years ago

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Can someone help with this math word problem.

iragen [17]

Answer:

Step-by-step explanation:

Time taken to eat the pizza in seconds =28×60=1680 seconds

If it takes 20seconds to lift, bite and chew,

Then the total bites taken to finish the pizza =1680/20 =84 bites

If for each bite 9cm² disappeared, then area that disappeared for 84bites =84×9cm² = 756cm²

Total area of pizza =756cm²

If area =(πd²)/4,

Then d² =(4×A)/π

d²=4×756/3.14=963.06

d=√963.06 = 31.03cm

1 centimeter=0.394inches

31.03cm= 0.394×31.03=12.23 inches ≈ 12inches(to the nearest inch)

The diameter of the pizza is 12inches

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Aggregating prospective buyers into groups that have common needs and will respond similarly to a marketing action is referred t

Elena-2011 [213]

Answer: Market segmentation

Step-by-step explanation:

Market segmentation involves dividing people based on their consumption behavior and grouping those with similar consumption behavior together . Market segmentation helps to boost sales , increase profit and enables the business attend to the customers in a better way .

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3 years ago

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