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3 years ago

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the area of a rectangle is 13 square inches. the length of the rectangle is 3.25 inches. what is the width of the rectangle? wha

t is the perimeter of the rectangle?

1 answer:

IrinaK [193]3 years ago

4 0

since the area of the rectangle is 13 square inches and the length is 3.25 inches subtract 3.25 from 13

$13 - 3.25 = 9.75$

which makes your width 9.75

to find the perimeter you add

9.75 + 3.25 + 9.75 + 3.25= 26.5

The perimeter of the rectangle is 26.5

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Angelina_Jolie [31]

Answer:

Amplitude = 1

Period = pi/2

Horizontal (phase) shift = pi

units Vertical shift = 0 units

right

Step-by-step explanation:

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3 years ago

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Of 580580 samples of seafood purchased from various kinds of food stores in different regions of a country and genetically compa

Lubov Fominskaja [6]

Answer:

a) The 99% confidence interval would be given (0.204;0.296).

b) We have 99% of confidence that the true population proportion of all seafood sold in the country that is mislabeled or misidentified is between (0.204;0.296).

c) No that's not true. Because the necessary assumptions and conditions for the confidence interval for the proportion are satisifed, so then we can use inferential statistics to interpret the interval to the population of interest.

Step-by-step explanation:

Part a

Data given and notation

n=580 represent the random sample taken

X represent the seafood sold in the country that is mislabeled or misidentified by the people

$\hat p=0.25$ estimated proportion of seafood sold in the country that is mislabeled or misidentified by the people

$\alpha=0.01$ represent the significance level (no given, but is assumed)

p= population proportion of seafood sold in the country that is mislabeled or misidentified by the people

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".

The population proportion have the following distribution

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

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 99% confidence interval the value of $\alpha=1-0.99=0.01$ and $\alpha/2=0.005$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=2.58$

And replacing into the confidence interval formula we got:

$0.25 - 2.58 \sqrt{\frac{0.25(1-0.25)}{580}}=0.204$

$0.25 + 2.58 \sqrt{\frac{0.25(1-0.25)}{580}}=0.296$

And the 99% confidence interval would be given (0.204;0.296).

Part b

We have 99% of confidence that the true population proportion of all seafood sold in the country that is mislabeled or misidentified is between (0.204;0.296).

Part c

A government spokesperson claimed that the sample size was too small, relative to the billions of pieces of seafood sold each year, to generalize. Is this criticism valid?

No that's not true. Because the necessary assumptions and conditions for the confidence interval for the proportion are satisifed, so then we can use inferential statistics to interpret the interval to the population of interest.

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3 years ago

Triangles DEF and D'E'F' are shown on the coordinate plane below: . . Triangle DEF and triangle D prime E prime F prime with ord

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<span><u><em>The correct answer is:</em></u>
180</span>°<span> rotation.

<u><em>Explanation: </em></u>
<span>Comparing the points D, E and F to D', E' and F', we see that the x- and y-coordinates of each <u>have been negated</u>, but they are still <u>in the same position in the ordered pair. </u>

<u>A 90</u></span></span><u>°</u><span><span><u> rotation counterclockwise</u> will take coordinates (x, y) and map them to (-y, x), negating the y-coordinate and swapping the x- and y-coordinates.

<u> A 90</u></span></span><u>°</u><span><span><u> rotation clockwise</u> will map coordinates (x, y) to (y, -x), negating the x-coordinate and swapping the x- and y-coordinates.

Performing either of these would leave our image with a coordinate that needs negated, as well as needing to swap the coordinates back around.

This means we would have to perform <u>the same rotation again</u>; if we began with 90</span></span>°<span><span> clockwise, we would rotate 90 degrees clockwise again; if we began with 90</span></span>°<span><span> counter-clockwise, we would rotate 90 degrees counterclockwise again. Either way this rotates the figure a total of 180</span></span>°<span><span> and gives us the desired coordinates.</span></span>

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2 years ago

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krok68 [10]

The answer is 68 because is repeating 3 times

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3 years ago

A cylinder has radius r and height h. A. How many times greater is the surface area of a cylinder when both dimensions are multi

Ierofanga [76]

Answer: A. Factor 2 => 4x greater

Factor 3 => 9x greater

Factor 5 => 25x greater

Step-by-step explanation: A. A cylinder is formed by 2 circles and a rectangle in the middle. That's why surface area is given by circumference of a circle, which is the length of the rectangle times height of the rectangle, i.e.:

A = 2.π.r.h

A cylinder of radius r and height h has area:

$A_{1}$ = 2πrh

If multiply both dimensions <u>by a factor of 2</u>:

$A_{2}$ = 2.π.2r.2h

$A_{2}$ = 8πrh

Comparing $A_{1}$ to $A_{2}$ :

$\frac{A_{2}}{A_{1}}$ = $\frac{8.\pi.rh}{2.\pi.rh}$ = 4

Doubling radius and height creates a surface area of a cylinder 4 times greater.

<u>By factor 3:</u>

$A_{3} = 2.\pi.3r.3h$

$A_{3} = 18.\pi.r.h$

Comparing areas:

$\frac{A_{3}}{A_{1}}$ = $\frac{18.\pi.r.h}{2.\pi.r.h}$ = 9

Multiplying by 3, gives an area 9 times bigger.

<u>By factor 5</u>:

$A_{5} = 2.\pi.5r.5h$

$A_{5} = 50.\pi.r.h$

Comparing:

$\frac{A_{5}}{A_{1}}$ = $\frac{50.\pi.r.h}{2.\pi.r.h}$ = 25

The new area is 25 times greater.

B. By analysing how many times greater and the factor that the dimensions are multiplied, you can notice the increase in area is factor². For example, when multiplied by a factor of 2, the new area is 4 times greater.

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3 years ago