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3 years ago

49 POINTS!!!!!!!!

1 answer:

3 0

The answer is II and III, which is the last choice from above. This is because the symbol "less than (or equal to)" indicated a conjunction, which means we have to take into account that the absolute value can be less than or equal to 15, and greater than or equal to -15. This solution set falls in between the two values, hence, the conjunction.

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How to work -1x-2y=-13 x-2y=11 equation by substitution

Norma-Jean [14]

Well if you're wanting to use substitution, you first have to end up with one term on either side of the equation. Use the second one as it's easiest.

So: x-2y=11, so find -2y as there is a -2y in the first equation.
then that becomes -2y=11-x. then sub that into equation 1, and you get:

-x+11-x=-13, which equals to -2x+11=-13, which is -2x=-24, so therefore

x=12. then chuck the x into any of the equations to find what y equals.

hope this helps!

5 0

3 years ago

If 540 people preferred pizzia, how many people preferred hamburgers

Licemer1 [7]

Answer:

900 people preferred hamburgers.

Step-by-step explanation:

540/x=60/100

cross multiply

60x=54,000 then

60x/60=54,000/60

x=900

so 900 people preferred hamburger

8 0

3 years ago

The proprietor of a boutique in New York wanted to determine the average age of his customers. A random sample of 25 customers r

jolli1 [7]

Answer:

$28-2.064\frac{10}{\sqrt{25}}=23.872$

$28+2.064\frac{10}{\sqrt{25}}=32.128$

So on this case the 95% confidence interval would be given by (23.9;32.1)

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".

$\bar X=28$ represent the sample mean

$\mu$ population mean (variable of interest)

s=10 represent the sample standard deviation

n=25 represent the sample size

Solution to the problem

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

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

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=25-1=24$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,24)".And we see that $t_{\alpha/2}=2.064$

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

$28-2.064\frac{10}{\sqrt{25}}=23.872$

$28+2.064\frac{10}{\sqrt{25}}=32.128$

So on this case the 95% confidence interval would be given by (23.9;32.1)

7 0

3 years ago

Which of the following is not a tool that can be used in a true Geometric construction? a)Protractor b)Compass c)Straightedge

AleksAgata [21]

Answer:

A) Protractor

Step-by-step explanation:

In Mathematics, geometric constructions refers to the drawing of geometric shapes, lines and angles with the exclusive aid of a pencil, straightedge/ruler and a pair of compass.

The pencil is the major drawing tool during the construction while the pair of compass and straightedge are used to construct arcs/circles and straight lines respectively. Note that, a PROTRACTOR is not needed in a geometric construction because length or angle measurements are prohibited.

4 0

3 years ago

Read 2 more answers

Please help

Elena-2011 [213]

Answer:

Step-by-step explanation:

The distance formula is:

$d = \sqrt{(x2 - x1)^2 + (y2 - y1)^2$