At a football stadium, 10% of the fans in attendance were teenagers. If there were 330

Candidate A is facing two opposing candidates in a mayoral election. In a recent poll of 300 residents, 98 supported candidate B

babymother [125]

Answer:

[0.4235, 0.5365]

Step-by-step explanation:

Data given and notation

n=300 represent the random sample taken

X=300-98-58=144 represent the people that support the candidate A in the sample

$\hat p=\frac{144}{300}=0.48$ estimated proportion of people that support the candidate A in the sample

$\alpha=0.05$ represent the significance level

Confidence =0.95 or 95%

p= population proportion of people that support the candidate A.

Confidence interval

The confidence interval would be given by this formula

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 95% confidence interval the value of $\alpha=1-0.95=0.05$ and $\alpha/2=0.025$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=1.96$

And replacing into the confidence interval formula we got:

$0.48 - 1.96 \sqrt{\frac{0.48(1-0.48)}{300}}=0.4235$

$0.48 + 1.96 \sqrt{\frac{0.48(1-0.48)}{300}}=0.5365$

And the 95% confidence interval would be given (0.4235;0.5365).

$0.4235 \leq p \leq 0.5365$

8 0

2 years ago

A golden rectangle is 32cm long.The ratio of length to width is (1 + square root of 5) :2. What is the width of the rectangle in

zhannawk [14.2K]

Answer:

Width = 16(√5) - 1

Step-by-step explanation:

We are told that the golden rectangle is 32 cm long.

Thus, length = 32 cm

We are also told that the ratio of the length to the width is; (1 + √5):2

Thus;

If a length of (1 + √5) yields a width of 2

Then, a length of 32 cm would yield a width of; (32 x 2)/(1 + √5)

So corresponding width = 64/(1 + √5)

We want to reduce this width to it's simplest radical form which means the denominator should have no square root.

Thus, let's multiply top and bottom by (1 - √5);

Width = 64 x (1 - √5)/[(1 + √5) x (1 - √5)]

Width = 64(1 - √5)/(1 - 5)

Width = 64(1 - √5)/(-4)

Width = -16(1 - √5)

Width = 16(√5 - 1)

Width = 16√5 - 1

8 0

2 years ago

Which statements describe a residual plot for a line of best fit that is a good model for a scatterplot? Check all that apply. T

lidiya [134]

Answer:

The points are randomly scattered with no clear pattern

The number of points is equal to those in the scatterplot.

Step-by-step explanation:

The points in the residual plot of the line of best fit that is a good model for a scatterplot are randomly scattered with no clear pattern (like a line or a curve).

The number of points in the residual plot is always equal to those in the scatterplot.

It doesn't matter if there are about the same number of points above the x-axis as below it, in the residual plot.

The y-coordinates of the points are not the same as the points in the scatterplot.

8 0

2 years ago

Read 2 more answers

Given △DEF, which is not equal to cos(F)? sin(F). sin(D). tan(F). cos(D)

valentina_108 [34]

Answer: The correct option is tan(F).

Explanation:

In the given figure the triangle is a right angle triangle because $\angle E=90^{\circ}$ .

It is also given that $DE=EF=5$ and $DF=5\sqrt{2}$ .

Since it is an isosceles right angle triangle, therefore the value of perpendicular and base is same for both angles D and F, which is 5.

$\cos (F)=\frac{Base}{Hypotenuse} =\frac{5}{5\sqrt{2}} =\frac{1}{\sqrt{2}}$

The value of cos(F) is $\frac{1}{\sqrt{2}}$ .

$\sin (F)=\frac{Perpendicular}{Hypotenuse} =\frac{5}{5\sqrt{2}} =\frac{1}{\sqrt{2}}$

The value of sin(F) is $\frac{1}{\sqrt{2}}$ .

$\sin (D)=\frac{Perpendicular}{Hypotenuse} =\frac{5}{5\sqrt{2}} =\frac{1}{\sqrt{2}}$

The value of sin(D) is $\frac{1}{\sqrt{2}}$ .

$\tan (F)=\frac{Perpendicular}{Base}=\frac{5}{5} =1$

The value of tan(F) is 1. Which is not equal to $\frac{1}{\sqrt{2}}$ .

$\cos (D)=\frac{Base}{Hypotenuse} =\frac{5}{5\sqrt{2}} =\frac{1}{\sqrt{2}}$

The value of cos(D) is $\frac{1}{\sqrt{2}}$ .

Therefore, the value of tan(F) is not equal to the value of cos(F), so the correct option is third.

3 0

2 years ago

Read 2 more answers

Find the volume V of the solid obtained by rotating the region bounded by the given curves about the specified line. y = 1 + sec

masha68 [24]

Using the washer method, the volume is given by the integral

$\displaystyle\pi\int_{-\pi/3}^{\pi/3}\bigg((3-1)^2-((1+\sec x)-1)^2\bigg)\,\mathrm dx=2\pi\int_0^{\pi/3}(4-\sec^2x)\,\mathrm dx$

where 3 - 1 = 2 is the distance from y = 3 to the axis of revolution, and similarly (1 + sec(x)) - 1 = sec(x) is the distance from y = 1 + sec(x) to the axis. The integrand is symmetric about x = 0, so the integral "folds" in on itself, and the integral from -π/3 to π/3 is twice the integral from 0 to π/3.

So the volume is

$\displaystyle2\pi\int_0^{\pi/3}(4-\sec^2x)\,\mathrm dx=2\pi(4x-\tan x)\bigg|_0^{\pi/3}=\boxed{\dfrac{8\pi^2}3-2\pi\sqrt3}$

4 0

2 years ago