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3 years ago

What is the solution to the equation 13×3/4+x=7(1/4)

1 answer:

5 0

I'm going to assume you mean:

13 * (3/4) + x = 7 * (1/4)

Let's go ahead and simplify the right side.

7 * (1/4) = 1.75

So now we have:

13 * (3/4) + x = 1.75

Now let's take care of the right side. Multiplication before addition.

13 * (3/4) = 9.75

9.75 + x = 1.75

To isolate x, we subtract 9.75 from both sides.

9.75 - 9.75 + x = 1.75 - 9.75

x = -8

Hopefully I spaced this well. \('-')/

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A. Y=-5/2x+2<br> B. Y=2/5x+2<br> C. Y=-2/5x+2<br> D. Y=5/2x+2

FrozenT [24]

Answer:
B. Y=2/5x+2

Explanation:
Y-intercept: (0,2)
Slope: 4-2. 2
——=
5-0. 5
Y=2/5+2

5 0

4 years ago

Read 2 more answers

Eric reflected parallelogram ABCD across the x-axis. If angle A is 125° and angle B is 55°, what is the degree measurement of an

Sauron [17]

The measures of the angles don't change when you translate a figure, because the entire figure is moving as a whole. Imagine having a paper parallelogram, moving it around and flipping it over. Not even dilations would change these angles (for reasons that can be pretty easily visualed but not really proven until geometry)

$m\angle A'=125\°$

7 0

4 years ago

In an examination of purchasing patterns of shoppers, a sample of 16 shoppers revealed that they spent, on average, $54 per hour

Lesechka [4]

Answer:

$54-1.64\frac{21}{\sqrt{16}}=45.39$

$54 +1.64\frac{21}{\sqrt{16}}=62.61$

So on this case the 90% confidence interval would be given by (45.39;62.61)

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".

$\bar X=54$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=21$ represent the sample standard deviation

n=16 represent the sample size

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since the Confidence is 0.90 or 90%, the value of $\alpha=1-0.9=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.05,0,1)".And we see that $z_{\alpha/2}=1.64$

Now we have everything in order to replace into formula (1):

$54-1.64\frac{21}{\sqrt{16}}=45.39$

$54 +1.64\frac{21}{\sqrt{16}}=62.61$

So on this case the 90% confidence interval would be given by (45.39;62.61)

4 0

4 years ago

Twice the difference of a number and seven

levacccp [35]

The difference of a number and seven is x - 7. So twice that, would be:

2(x - 7)

4 0

3 years ago

Consider an urn containing 8 white balls, 7 red balls and 5 black balls.

weqwewe [10]

Answer + Step-by-step explanation:

1) The probability of getting 2 white balls is equal to:

$=\frac{8}{20} \times \frac{7}{19}\\\\= 0.147368421053$

2) the probability of getting 2 white balls is equal to:

$=C^{2}_{5}\times (\frac{8}{20} \times \frac{7}{19}) \times (\frac{12}{18} \times \frac{11}{17} \times \frac{10}{16})\\=0.397316821465$

3) The probability of getting at least 72 white balls is:

$=C^{72}_{150}\times \left( \frac{8}{20} \right)^{72} \times \left( \frac{7}{20} \right)^{78} +C^{73}_{150}\times \left( \frac{8}{20} \right)^{73} \times \left( \frac{7}{20} \right)^{77} + \cdots +C^{149}_{150}\times \left( \frac{8}{20} \right)^{149} \times \left( \frac{7}{20} \right)^{1} +\left( \frac{8}{20} \right)^{150}$

$=\sum^{150}_{k=72} [C^{k}_{150}\times \left( \frac{8}{15} \right)^{k} \times \left( \frac{7}{15} \right)^{150-k}]$

5 0

1 year ago

Read 2 more answers