Consider the quadratic function that has x-intercepts of -1 and -7 and passes through the point (-2, -20). What is

I need help with this someone!!

Alex

Answer:

Do u have answer choices?

4 0

3 years ago

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Points (3,2) and (-5,6) are endpoints of the diameter of a circle.

vichka [17]

Answer:

A.8 B.(-1,4) C.(1,4)

Step-by-step explanation:

First, know that (3,2)=(x1,y1) and (-5,6)=(x2,y2)

A. The diameter is 8, given the diference between x1 and x2: 3-(-5)=8

B. The center point is given by (x1+x2)/2 and (y1+y2)/2

(x1+x2)/2 and (y1+y2)/2 = (3-5)/2 and (2+6)/2 = (-1,4)

C. The symmetric point of C about the x-axis is (1,4)

5 0

2 years ago

How do I find the Axis of Symmetry for a parabola

soldier1979 [14.2K]

Answer:

Explanation given below.

Step-by-step explanation:

The first step is to put the parabola in the form $ax^2+bx+c$ , which is the standard form of a parabola

Note: a is the coefficient before x^2 term, b is the coefficient before x term, and c is the independent constant term

The axis of symmetry divides the parabola symmetrically. The axis of symmetry has the equation $x=-\frac{b}{2a}$

Where a and b are the respective values shown above

So, that is how you get the axis of symmetry of any parabola.

4 0

2 years ago

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In a set of data, if there is no clear pattern to the points when graphed on a coordinate plane, we say there is no relative ___

VikaD [51]

Answer: If there is no clear pattern to the points when graphed on a coordinate plane, we say there is no relative correlation.

In a scatter plot, we are looking for a pattern (or correlation) between the points. Sometimes, they increase together. Sometimes, they decrease together.

If we can't see a pattern, we say there is no correlation.

7 0

3 years ago

In March 2015, the Public Policy Institute of California (PPIC) surveyed 7525 likely voters living in California. This is the 14

lbvjy [14]

Answer:

We are confident at 99% that the difference between the two proportions is between $0.380 \leq p_{Republicans} -p_{Democrats} \leq 0.420$

Step-by-step explanation:

Part a

Data given and notation

$X_{D}=3266$ represent the number people registered as Democrats

$X_{R}=2137$ represent the number of people registered as Republicans

$n=7525$ sampleselcted

$\hat p_{D}=\frac{3266}{7525}=0.434$ represent the proportion of people registered as Democrats

$\hat p_{R}=\frac{2137}{7525}=0.284$ represent the proportion of people registered as Republicans

The standard error is given by this formula:

$SE=\sqrt{\frac{\hat p_D (1-\hat p_D)}{n_{D}}+\frac{\hat p_R (1-\hat p_R)}{n_{R}}}$

And the standard error estimated given by the problem is 0.008

Part b

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".

$p_A$ represent the real population proportion of Democrats that approve of the way the California Legislature is handling its job

$\hat p_A =\frac{1894}{3266}=0.580$ represent the estimated proportion of Democrats that approve of the way the California Legislature is handling its job

$n_A=3266$ is the sample size for Democrats

$p_B$ represent the real population proportion of Republicans that approve of the way the California Legislature is handling its job

$\hat p_B =\frac{385}{2137}=0.180$ represent the estimated proportion of Republicans that approve of the way the California Legislature is handling its job

$n_B=2137$ is the sample for Republicans

$z$ represent the critical value for the margin of error

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

The confidence interval for the difference of two proportions would be given by this formula

$(\hat p_A -\hat p_B) \pm z_{\alpha/2} \sqrt{\frac{\hat p_A(1-\hat p_A)}{n_A} +\frac{\hat p_B (1-\hat p_B)}{n_B}}$

For the 90% confidence interval the value of $\alpha=1-0.90=0.1$ and $\alpha/2=0.05$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=1.64$

And replacing into the confidence interval formula we got:

$(0.580-0.180) - 1.64 \sqrt{\frac{0.580(1-0.580)}{3266} +\frac{0.180(1-0.180)}{2137}}=0.380$

$(0.580-0.180) + 1.64 \sqrt{\frac{0.580(1-0.580)}{3266} +\frac{0.180(1-0.180)}{2137}}=0.420$

And the 99% confidence interval would be given (0.380;0.420).

We are confident at 99% that the difference between the two proportions is between $0.380 \leq p_{Republicans} -p_{Democrats} \leq 0.420$

5 0

3 years ago