Solve the system of equations by graphing: x + 2y = 4 and 4x

$800 at 3.8% interest for 6 months<br> What is the interest?<br><br> What is the new balance?

Furkat [3]

Use the equation I/PT = R I is the interest P is the money before investment and T is the time

4 0

3 years ago

Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther.â Suppose a small group of 11 Allen's humming

alexira [117]

Answer:

$3.15-1.28\frac{0.38}{\sqrt{11}}=3.003$

$3.15+ 1.28\frac{0.38}{\sqrt{11}}=3.297$

So on this case the 80% confidence interval would be given by (3.003;3.297)

And the margin of error is given by:

$ME = 1.28\frac{0.38}{\sqrt{11}}= 0.147$

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".

$\bar X=3.15$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=0.38$ represent the population standard deviation

n=11 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 0.80 or 80%, the value of $\alpha=0.2$ and $\alpha/2 =0.1$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NOR.INV(0.1,0,1)".And we see that $z_{\alpha/2}=1.28$

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

$3.15-1.28\frac{0.38}{\sqrt{11}}=3.003$

$3.15+ 1.28\frac{0.38}{\sqrt{11}}=3.297$

So on this case the 80% confidence interval would be given by (3.003;3.297)

And the margin of error is given by:

$ME = 1.28\frac{0.38}{\sqrt{11}}= 0.147$

8 0

3 years ago

Given ABCE is a rectangle, D is the midpoint of CE<br> Prove AD =~ BD

Bas_tet [7]

Since the congruent operator is â‰… and since AD is congruent to BD, I'm going to assume that you want to prove that AD is congruent to BD.
1. DE is equal to CD by definition since D is the midpoint of CE.
2. AE is equal to BC since opposite sides of a rectangle are equal to each other.
3. Angle AEC is equal to Angle BCE since all angles in a rectangle are right angles and all right angles are equal to each other.
4. Triangles ADE and BDC are congruent to each other because we have SAS congruence for both triangles.
5. AD is congruent to BC since they're corresponding sides of congruent triangles.

5 0

3 years ago

Witch method will not get you to the point (5,2.5) ?

ICE Princess25 [194]

Answer:

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Step-by-step explanation:

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5 0

4 years ago

Lewis is planning a cycling holiday.

galben [10]

Answer:

72 miles/day

Step-by-step explanation:

12 m/hr * 6 hr / day = 72 mi/day

8 0

2 years ago

Solve the system of equations by graphing: x + 2y = 4 and 4x - 2y = 16