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3 years ago

. Charlotte buys two biscuits and a carton of milk for $5.00.

2 answers:

5 0

Let’s make a system of equation
b = biscuit, c = carton of milk
2b + c = 5.00
3b + c = 6.50
Now use elimination subtract
-1b = -1.5
b = $1.50
2(1.50) + c = 5
3 + c = 5, c= $2.00
Solution: $0.50 more

ivolga24 [154]3 years ago

4 0

Answer:

$0.50

Step-by-step explanation:

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A line with a slope of 0 contains the point (3,4) . The point -2,? is also on the line. What is the missing y-coordinate?

KatRina [158]

Answer:

Step-by-step explanation:

If the slope is 0, the line is horizontal and the y-coordinate is 4 for all x values.

Thus the missing y-coordinate is 4.

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3 years ago

Nitrates are groundwater contaminants derived from fertilizer, septic tank seepage and other sewage. Nitrate poisoning is partic

o-na [289]

Answer:

a) $n=\frac{0.5(1-0.5)}{(\frac{0.02}{1.96})^2}=2401$

And rounded up we have that n=2401

b) $n=\frac{0.07(1-0.07)}{(\frac{0.02}{1.96})^2}=625.22$

And rounded up we have that n=626

And we see that if we have previous info about p the sample size varies a lot.

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

Solution to the problem

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical value would be given by:

$z_{\alpha/2}=-1.96, z_{1-\alpha/2}=1.96$

Part a

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.02$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

Since we don't have prior information about the population proportion we can use ase estimator $\hat p =0.5$ . And replacing into equation (b) the values from part a we got:

$n=\frac{0.5(1-0.5)}{(\frac{0.02}{1.96})^2}=2401$

And rounded up we have that n=2401

Part b

For thi case the estimator for p is $\hat p =0.07$

$n=\frac{0.07(1-0.07)}{(\frac{0.02}{1.96})^2}=625.22$

And rounded up we have that n=626

And we see that if we have previous info about p the sample size varies a lot.

4 0

3 years ago

5x-60 = -60 +2x +3x how many solutions does the equation have

xeze [42]

Answer:

$infinitely \: many \: solution$

Step-by-step explanation:

1) Cancle -60 on both sides.

$5x = 2x + 3x$

2) Simplify 2x + 3x to 5x.

$5x = 5x$

3) Since both sides are equal, there are infinitely many solutions.

$infinietly \: many \: solution$

Therefor, this equation has infinitely many solutions.

5 0

3 years ago

A pair of shoes cost $22.99 to make, the local store sells them for $36.99. What is the percent markup? (Round to the nearest hu

ASHA 777 [7]

C: 60.9% is the right answer

Step-by-step explanation:

The markup is calculated by using the formula

$Mark\ up=Selling\ price-make\ price$

Given

Make Price = $22.99

Selling Price = $36.99

So the mark up will be:

$Mark\ up=36.99-22.99\\=\$14$

Percent mark up will be:

$Mark\ up=\frac{Mark\ up}{Make\ price}*100\\=\frac{14}{22.99}*100\\=0.6089*100\\=60.89\%$

Rounding off to the nearest hundredth percent

60.9%

Hence,

C: 60.9% is the right answer

Keywords: Markup, Percentage

Learn more about percentage at:

#LearnwithBrainly

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3 years ago

How can you prove: secθ = cscθtanθ

zavuch27 [327]

$\sec \theta=\csc \theta\tan \theta\\\\ \dfrac{1}{\cos \theta}=\dfrac{1}{\sin \theta}\cdot\dfrac{\sin \theta}{\cos \theta}\\\\ \dfrac{1}{\cos \theta}=\dfrac{1}{\cos \theta}$

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3 years ago