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1 year ago

Hi, can you help me answer this question please, thank you

Mathematics

1 answer:

saveliy_v [14]1 year ago

3 0

Given:

Confidence level of 98%

$n=31\text{ ; }\bar{\text{x}}=33\text{ and s=2}$

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Solve with elimination

Fittoniya [83]

I'm pretty sure this is correct

4 0

4 years ago

Assume you have noted the following prices for books and the number of pages that each book contains. Book Pages (x) Price (y) A

belka [17]

Answer:

a) $y=0.00991 x +1.042$

b) $r^2 = 0.7503^2 = 0.563$

c) $r=\frac{7(30095)-(4210)(49)}{\sqrt{[7(2595100) -(4210)^2][7(354) -(49)^2]}}=0.7503$

Step-by-step explanation:

Data given

x: 500, 700, 750, 590 , 540, 650, 480

y: 7.00, 7.50 , 9.00, 6.5, 7.50 , 7.0, 4.50

Part a

We want to create a linear model like this :

$y = mx +b$

Wehre

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

And:

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

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

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=2595100-\frac{4210^2}{7}=63085.714$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i){n}}=30095-\frac{4210*49}{7}=625$

And the slope would be:

$m=\frac{625}{63085.714}=0.00991$

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

$\bar x= \frac{\sum x_i}{n}=\frac{4210}{7}=601.429$

$\bar y= \frac{\sum y_i}{n}=\frac{49}{7}=7$

And we can find the intercept using this:

$b=\bar y -m \bar x=7-(0.00991*601.429)=1.042$

And the line would be:

$y=0.00991 x +1.042$

Part b

The correlation coefficient is given by:

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

For our case we have this:

n=7 $\sum x = 4210, \sum y = 49, \sum xy = 30095, \sum x^2 =2595100, \sum y^2 =354$

$r=\frac{7(30095)-(4210)(49)}{\sqrt{[7(2595100) -(4210)^2][7(354) -(49)^2]}}=0.7503$

The determination coefficient is given by:

$r^2 = 0.7503^2 = 0.563$

Part c

$r=\frac{7(30095)-(4210)(49)}{\sqrt{[7(2595100) -(4210)^2][7(354) -(49)^2]}}=0.7503$

4 0

3 years ago

A paint store sells exterior paint for $35.75 a gallon and paint rollers for $6.00 each. Write an equation in standard form for

VLD [36.1K]

The total price for the gallons of paint will be 35.75p

The total price for the rollers will be 6r

So the equation if the customer have 190 will be
price for gallons of paint + price for rollers = 190
35.75p + 6r = 190
<em>(This is the equation)</em>

3 0

3 years ago

When looking at a problem how can you tell if it is a power of power rule or power of product rule

LiRa [457]

Power of power rule:

Zero-Exponent Rule: a0 = 1, this says that anything raised to the zero power is 1. Power Rule (Powers to Powers): (am)n = amn, this says that to raise a power to a power you need to multiply the exponents. ... Only move the negative exponents.

Power of product rule:

The exponent "product rule" tells us that, when multiplying two powers that have the same base, you can add the exponents. ... Adding the exponents is just a short cut! Power Rule. The "power rule" tells us that to raise a power to a power, just multiply the exponents.

8 0

3 years ago

A pair of sneakers costs $60. Dahlia bought them on sale

marishachu [46]

Answer:

The answer is 25%

Step-by-step explanation:

8 0

3 years ago

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