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1 year ago

Jalen inherited a collection of vintage comic books. An appraiser separated the comic

Mathematics

1 answer:

sladkih [1.3K]1 year ago

7 0

Jalen has total 63 comic books.

Step-by-step explanation:

Given,

Total value of comic books = $3135

Let,

Number of $45 comic books = x

Number of $65 comic books = y

According to given statement;

45x+65y=3135 Eqn 1

x=y+33 Eqn 2

Putting value of x from Eqn 2 in Eqn 1

$45(y+33)+65y=3135\\45y+1485+65y=3135\\110y=3135-1485\\110y=1650\\$

Dividing both sides by 110

$\frac{110y}{110}=\frac{1650}{110}\\y=15$

Putting y=15 in Eqn 2

$x=15+33\\x=48$

Total comic books = x+y

Total comic books = 48+15 = 63

Jalen has total 63 comic books.

Keywords: addition, elimination method

Learn more about elimination method at:

#LearnwithBrainly

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Which test point holds true for y − 2x ≤ 1?

CaHeK987 [17]

So in order to find the correct answer, we can just easily plug in the values to check which ordered pair matches the given inequality above. So based on my solutions, the correct answer would be the last pair.
<span> y − 2x ≤ 1
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1 year ago

The line 3y+x=25 is a normal to the curve y=x2-5x+k.find the value of constant k.

ladessa [460]

Answer:

k = 11.

Step-by-step explanation:

y = x^2 - 5x + k

dy/dx = 2x - 5 = the slope of the tangent to the curve

The slope of the normal = -1/(2x - 5)

The line 3y + x =25 is normal to the curve so finding its slope:

3y = 25 - x

y = -1/3 x + 25/3 <------- Slope is -1/3

So at the point of intersection with the curve, if the line is normal to the curve:

-1/3 = -1 / (2x - 5)

2x - 5 = 3 giving x = 4.

Substituting for x in y = x^2 - 5x + k:

When x = 4, y = (4)^2 - 5*4 + k

y = 16 - 20 + k

so y = k - 4.

From the equation y = -1/3 x + 25/3, at x = 4

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2 years ago

A member of a student team playing an interactive marketing game received the fol- lowing computer output when studying the rela

nirvana33 [79]

Answer:

$p_v = 2*P(t_{n-2} > |t_{calc}|)= 0.91$

So on this case for the significance level assumed $\alpha=0.05$ we see that $p_v >\alpha$ so then we can conclude that the result is NOT significant. And we don't have enough evidence to reject the null hypothesis.

So on this case is not appropiate say that :"the more we spend on advertising this product, the fewer units we sell" since the slope for this case is not significant.

Step-by-step explanation:

Let's suppose that we have the following linear model:

$y= \beta_o +\beta_1 X$

Where Y is the dependent variable and X the independent variable. $\beta_0$ represent the intercept and $\beta_1$ the slope.

In order to estimate the coefficients $\beta_0 ,\beta_1$ we can use least squares procedure.

If we are interested in analyze if we have a significant relationship between the dependent and the independent variable we can use the following system of hypothesis:

Null Hypothesis: $\beta_1 = 0$

Alternative hypothesis: $\beta_1 \neq 0$

Or in other words we want to check is our slope is significant (X have an effect in the Y variable )

In order to conduct this test we are assuming the following conditions:

a) We have linear relationship between Y and X

b) We have the same probability distribution for the variable Y with the same deviation for each value of the independent variable

c) We assume that the Y values are independent and the distribution of Y is normal

The significance level assumed on this case is $\alpha=0.05$

The standard error for the slope is given by this formula:

$SE_{\beta_1}=\frac{\sqrt{\frac{\sum (y_i -\hat y_i)^2}{n-2}}}{\sqrt{\sum (X_i -\bar X)^2}}$

Th degrees of freedom for a linear regression is given by $df=n-2$ since we need to estimate the value for the slope and the intercept.

In order to test the hypothesis the statistic is given by:

$t=\frac{\hat \beta_1}{SE_{\beta_1}}$

The p value on this case would be given by:

$p_v = 2*P(t_{n-2} > |t_{calc}|)= 0.91$

So on this case is not appropiate say that :"the more we spend on advertising this product, the fewer units we sell" since the slope for this case is not significant.

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1 year ago

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olchik [2.2K]

To solve this problem, we should set up a proportion, letting x represent our unknown number of miles that Wayne walks in one hour.

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Now we use cross-products or the multiplication of the numerator of one fraction times the denominator of the other fraction, setting these two numbers equal. The resulting equation is:

1/6 = 1/10x

Finally, we must divide both sides by 1/10 to cancel it out on the right side of the equation and get the variable x alone.

x = 5/3 or 1 2/3

Therefore, Wayne walks 1 2/3 miles per hour.

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1 year ago

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