I don't understand this quadratic functions question please help.

I will mark you brainlist and give 5 stars! Please help!

mrs_skeptik [129]

Answer:

9A-F

9B-EI

9C-FG

Step-by-step explanation:

6 0

3 years ago

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Ashlyn had some Barbie dolls. Joslyn has 78 barbies. Rounded to the nearest ten, together they have 140 Barbie dolls. How many d

azamat

ashlyn has 60 barbie dolls

6 0

3 years ago

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An engineer is going to redesign an ejection seat for an airplane. The seat was designed for pilots weighing between 130 lb and

egoroff_w [7]

Answer:

a) $P(140$

$P(0.036$

b) $P(140< \bar X$

Step-by-step explanation:

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".

Part a

Let X the random variable that represent the weights of a population, and for this case we know the distribution for X is given by:

$X \sim N(139,28.1)$

Where $\mu=139$ and $\sigma=28.1$

We are interested on this probability

$P(140$

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

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

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

$P(140$

And we can find this probability like this:

$P(0.036$

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

$P(0.036$

Part b

For this case we select a sample size of n =32. Since the distribution for X is normal then the distribution for the sample mean $\bar X$ is given by:

$\bar X \sim N(\mu=139, \frac{\sigma}{\sqrt{n}}=\frac{28.1}{\sqrt{32}}=4.97)$

And the new z score would be:

$Z=\frac{\bar X -\mu}{\sigma_{\bar x}}$

$P(140< \bar X$

5 0

3 years ago

Help please will mark brainliest.

swat32

Answer: the ANSWER IS 11 sqt

Step-by-step explanation:

Factor 1331 into its prime factors

1331 = 113

To simplify a square root, we extract factors which are squares, i.e., factors that are raised to an even exponent.

Factors which will be extracted are :

121 = 112

Factors which will remain inside the root are :

11 = 11

To complete the simplification we take the squre root of the factors which are to be extracted. We do this by dividing their exponents by 2 :

11 = 11

The simplified SQRT looks like this:

11 • sqrt (11)

Simplified Root :

11 • sqrt(11)

7 0

3 years ago

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How do i solve 4x - 2y = 22 and 2x + 4y = 6 using substitution and elimination?

Fiesta28 [93]

substitution and elimination means that you need to use one equation and substitute it in place of some variable in the other equation.

Consider the above two equations.

Take equation 1, which is 4x-2y=22 => x=(22+2y)/4

substitute the x value gained above in equation 2.

so, 2((22+2y)/4)+4y=6

22+2y+8y=12 => 10y = -10 => y= -1.

Substitute y= -1 in x value obtained in the beginning.

So, x= (22 - 2)/4 => 5.

There fore, x= 5 and y= -1

Hope it helps.

5 0

3 years ago