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3 years ago

Evaluate 21 - n for n = 3 * please help me with this

Mathematics

2 answers:

Alinara [238K]3 years ago

8 0

21-3=18 because n=3 and you’re just subtracting

qwelly [4]3 years ago

4 0

Answer:

Step-by-step explanation:

21-n; n=3

Substitute n for 3:

21-3

Solve.

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Ignore my answer it probably isn't right

notka56 [123]

The answer to your question is 30\3. hope you have a good day. and make sure you eat and drink something.

3 0

3 years ago

Suppose a baker claims that the average bread height is more than 15cm. Several of this customers do not believe him. To persuad

laila [671]

Answer:

$17-2.262\frac{1.9}{\sqrt{10}}=15.641$

$17+2.262\frac{1.9}{\sqrt{10}}=18.359$

So on this case the 95% confidence interval would be given by (15.641;18.359)

And since the lower limit for the confidence interval is higher than 15 we can conclude that at 5% of significance the true mean is higher than 15 cm

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".

$\bar X=17$ represent the sample mean

$\mu$ population mean (variable of interest)

s=1.9 represent the sample standard deviation

n=10 represent the sample size

Confidence interval

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:

$df=n-1=10-1=9$

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(0.025,9)".And we see that $t_{\alpha/2}=2.262$

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

$17-2.262\frac{1.9}{\sqrt{10}}=15.641$

$17+2.262\frac{1.9}{\sqrt{10}}=18.359$

So on this case the 95% confidence interval would be given by (15.641;18.359)

And since the lower limit for the confidence interval is higher than 15 we can conclude that at 5% of significance the true mean is higher than 15 cm

4 0

3 years ago

Answer both please, the topic is linear inequalities, and please explain it to me.

Bogdan [553]

Question 1 solution:
You have two unknowns here:

Let the Water current speed = W

Let Rita's average speed = R

We are given two situations, where we can form two equations, and therefore solve for the two unknowns, W, R:

Part 1) W→ , R←(against current, upstream)
If Rita is paddling at 2mi/hr against the current, this means that the current is trying to slow her down. If you look at the direction of the water, it is "opposing" Rita, it is "opposite", therefore, our equation must have a negative sign for water:

R–W=2 - equation 1

Part 2) W→ , R→(with current)
Therefore, R+W=3 - equation 2

From equation 1, W=R-2,
Substitute into equation 2.
R+(R–2)=3
2R=5
R=5/2mi/hr

So when W=0 (still), R=5/2mi/hr

Finding the water speed using the same rearranging and substituting process:

1... R=2+W
2... (2+W)+W=3
2W=1
W=1/2mi/hr

7 0

3 years ago

An object moves at a constant rate. The graph shows the object's height at different times. Which equation represents the situat

zlopas [31]

d. y = 15x 900

Although you do not give the rates I assume the answer is D as it is the only positive multiplication. You cannot have negative height.

3 0

4 years ago

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Arrange the matrices in increasing order of their determinant values.

maksim [4K]

Answer:

Step-by-step explanation:

7 0

3 years ago

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