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3 years ago

What Is 2x squared minus 3x

Mathematics

1 answer:

Alex_Xolod [135]3 years ago

4 0

it equals an answer that answers the question

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What is the slope of y=-4x-3

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Using the slope-intercept form, the slope is 4 .

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3 years ago

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X+5 3 + x−5 2x+5 = x−5 3x

Lina20 [59]

Answer: 4x+5 $\neq$ 4x-5

Step-by-step explanation: It's really hard to tell what the question is.

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3 years ago

In a random sample of 25 people, the mean commute time to work was 33.9 minutes and the standard deviation was 7.2 minutes. Ass

Phoenix [80]

Answer:

$33.9-1.32\frac{7.2}{\sqrt{25}}=31.999$

$33.9+1.32\frac{7.2}{\sqrt{25}}=35.801$

So on this case the 80% confidence interval would be given by (31.999;35.801)

And the margin of error is given by:

$ME = t_{\alpha/2}\frac{s}{\sqrt{n}}$

And replacing we got:

$ME = 1.32\frac{7.2}{\sqrt{25}} =1.9008$

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".

$\bar X=33.9$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s=7.2 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 0.80 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: "=-T.INV(0.01,24)".And we see that $t_{\alpha/2}=1.32$

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

$33.9-1.32\frac{7.2}{\sqrt{25}}=31.999$

$33.9+1.32\frac{7.2}{\sqrt{25}}=35.801$

So on this case the 80% confidence interval would be given by (31.999;35.801)

And the margin of error is given by:

$ME = t_{\alpha/2}\frac{s}{\sqrt{n}}$

And replacing we got:

$ME = 1.32\frac{7.2}{\sqrt{25}} =1.9008$

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4 years ago

Meghan found 15 pieces of sea glass on the beach. The next day she found 4 more pieces than she found the day before. Write and

Hunter-Best [27]

Answer:

Step-by-step explanation:

15 + 4 = 19

19 + 15 = 34

(What do they mean estimate your answer?)

An estimation is 30(?)

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1 year ago

Jacob has saved $50. He spent $15 at th movies. Then after paying repairs to his bike, he has $0 remaining. How much did the bik

zmey [24]

Answer:

The bike repair costs $35

Step-by-step explanation:

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3 years ago