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3 years ago

12

Help with question 2 please.

1 answer:

Firdavs [7]3 years ago

3 0

Words would be "x is smaller than 1"

Algebra would be x < 1

Possible solutions are 0, -1, -2

Hope this helps.

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125cm to 87.5cm<br> URGENT<br> I WILL GIVE BRAINLIEST TO CORRECT ANSWER

Studentka2010 [4]

Answer:

30% decrease is the answer

7 0

3 years ago

At which point do the two equations

Lena [83]

The lines intersect at two places.

They intersect at approximately (-2,8) and (2,3)

Looking at the choices they would be at (1.8,3.2) and (-2.8,7.8)

The answer is D. Both A and B.

4 0

3 years ago

A simple random sample of size nequals=8181 is obtained from a population with mu equals 77μ=77 and sigma equals 27σ=27. (a) De

ivanzaharov [21]

Answer:

a) $P(\bar X>81.5)=1-0.933=0.067$

b) $P(\bar X$

c) $P(73.4$

Step-by-step explanation:

1) Previous concepts

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".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Let X the random variable that represent interest on this case, and for this case we know the distribution for X is given by:

$X \sim N(\mu=77,\sigma=27)$

And let $\bar X$ represent the sample mean, the distribution for the sample mean is given by:

$\bar X \sim N(\mu,\frac{\sigma}{\sqrt{n}})$

On this case $\bar X \sim N(77,\frac{27}{\sqrt{81}})$

Part a

We want this probability:

$P(\bar X>81.5)=1-P(\bar X$

The best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\frac{\sigma}{\sqrt{n}}}$

If we apply this formula to our probability we got this:

$P(\bar X >81.5)=1-P(Z$

$P(\bar X>81.5)=1-0.933=0.067$

Part b

We want this probability:

$P(\bar X\leq 69.5)$

If we apply the formula for the z score to our probability we got this:

$P(\bar X \leq 69.5)=P(Z\leq \frac{69.5-77}{\frac{27}{\sqrt{81}}})=P(Z$

$P(\bar X\leq 69.5)=0.0062$

Part c

We are interested on this probability

$P(73.4$

If we apply the Z score formula to our probability we got this:

$P(73.4$

$=P(\frac{73.4-77}{\frac{27}{\sqrt{81}}}$

And we can find this probability on this way:

$P(-1.2$

And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.

$P(-1.2$

3 0

4 years ago

What it 40x + 24? I can't figure this out.

Dmitrij [34]

8(5x+3)

If you miltiplied 8 x 5x it will give you 40 x

And 8 x 3 is 24

7 0

3 years ago

What is the solution set of x2 + 5x- 5 = 0? oss-355 S +385 o sus S* o {stay -S-345 , 30 O S=5+375 5+3/5 2 0 --375 -5 +385 2

jolli1 [7]

Given the quadratic equation:

$x^2+5x-5=0$

Using the general solution for quadratic equations:

$ax^2+bx+c=0\Rightarrow x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$

From the problem, we identify:

$\begin{gathered} a=1 \\ b=5 \\ c=-5 \end{gathered}$

Then:

$x=\frac{-5\pm\sqrt{25+20}}{2}=\frac{-5\pm3\sqrt{5}}{2}$

And the solution set is:

$\lbrack\frac{-5-3\sqrt{5}}{2},\frac{-5+3\sqrt{5}}{2}]$

6 0

1 year ago