All categories

2 years ago

Help please I am not understand

Mathematics

1 answer:

amm18122 years ago

6 0

Answer:

4.5 units

Step-by-step explanation:

The formula given is used to calculate the length of a segment given the coordinates of the endpoints.

let (x₁, y₁ ) = A(-1, 1) and (x₂, y₂ ) = (3,3), then

AB = $\sqrt{(3+1)^2+(3-1)^2}$

= $\sqrt{4^2+2^2}$

= $\sqrt{16+4}$ = $\sqrt{20}$ ≈ 4.5 ( nearest tenth )

You might be interested in

On a sunny day, cindy notices that her shadow is 21 inches long. if it is 75 inches from the top of her head to the end of the s

Ray Of Light [21]

Cindy is 72 inches long. Imagine it like a right triangle. Her shadow is the base, she is the side, and the distance between her head and the end of the shadow is the diagonal line connecting the two. Use the Pythagorean theorem to find how tall cindy is.

a²+b²=c²        a=21, the length of the shadow
                       b= ? cindy's height
                     c= 75, the distance from her head to the edge of the shadow
21²+ b²=75²
441 +b² = 5625
-441         -441
------         -------
0             5184
b² = 5184
√b² =√5184
b= 72

hope it helps

5 0

2 years ago

A survey organization has used the methods of our class to construct an approximate 95% confidence interval for the mean annual

lawyer [7]

Answer:

$\bar X = \frac{66000+70000}{2}= 68000$

We can estimate the margin of error with this formula:

$ME= \frac{Upper -Lower}{2}= \frac{70000-66000}{2}= 2000$

And the margin of error is given by:

$ME = z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$

And we can rewrite the margin of error like this:

$ME =z_{\alpha/2}*SE$

Where $SE= \frac{\sigma}{\sqrt{n}}$

For 95% of confidence the critical value is $z_{\alpha/2}= \pm 1.96$

The Standard error would be:

$SE= \frac{ME}{z_{\alpha/2}}= \frac{2000}{1.96}= 1020.408$

For 99% of confidence the critical value is $z_{\alpha/2}= \pm 2.58$

And the new margin of error would be:

$ME = 2.58* 1020.408 = 2632.653$

And then the interval would be given by:

$Lower = 68000- 2632.653 = 65367.347$

$Upper = 68000+ 2632.653 = 70632.653$

Step-by-step explanation:

Previous concepts

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".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

The 95% confidence interval is given by (66000 , 70000)

We can estimate the mean with this formula:

$\bar X = \frac{66000+70000}{2}= 68000$

We can estimate the margin of error with this formula:

$ME= \frac{Upper -Lower}{2}= \frac{70000-66000}{2}= 2000$

And the margin of error is given by:

$ME = z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$

And we can rewrite the margin of error like this:

$ME =z_{\alpha/2}*SE$

Where $SE= \frac{\sigma}{\sqrt{n}}$

For 95% of confidence the critical value is $z_{\alpha/2}= \pm 1.96$

The Standard error would be:

$SE= \frac{ME}{z_{\alpha/2}}= \frac{2000}{1.96}= 1020.408$

For 99% of confidence the critical value is $z_{\alpha/2}= \pm 2.58$

And the new margin of error would be:

$ME = 2.58* 1020.408 = 2632.653$

And then the interval would be given by:

$Lower = 68000- 2632.653 = 65367.347$

$Upper = 68000+ 2632.653 = 70632.653$

7 0

3 years ago

small cubes with edge lengths of 1/4 inch will be packed into the right rectangular prism shown.( the base is 4 1/2, the width i

ss7ja [257]

General Idea:

We need to find the volume of the small cube given the side length of the small cube as 1/4 inch.

Also we need to find the volume of the right rectangular prism with the given dimension (the height is 4 1/2, the width is 5, and the length is 3 3/4).

To find the number of small cubes that are needed to completely fill the right rectangular prism, we need to divide volume of right rectangular prism by volume of each small cube.

Formula Used:

$Volume \; of \; Cube = a^3 \; \\\{where \; a \; is \; side \; length \; of \; cube\}\\\\Volume \; of \; Right \; Rectangular \; Prism=L \times W \times H\\\{Where \; L \; is \; Length, \; W \; is \; Width, \;and \; H \; is \; Height\}$

Applying the concept:

Volume of Small Cube:

$V_{cube}= (\frac{1}{4} )^3= \frac{1}{64} \; in^3\\\\V_{Prism}= 3 \frac{3}{4} \times 5 \times 4 \frac{1}{2} = \frac{15}{4} \times \frac{5}{1} \times \frac{9}{2} = \frac{675}{8} \\\\Number \; of \; small \; cubes= \frac{V_{Prism}}{V_{Cube}} = \frac{675}{8} \div \frac{1}{64} \\\\Flip \; the \; second \; fraction\; and \; multiply \; with \; the \; first \; fraction\\\\Number \; of \; small \; cubes \;= \frac{675}{8} \times \frac{64}{1} = 5400$

Conclusion:

The number of small cubes with side length as 1/4 inches that are needed to completely fill the right rectangular prism whose height is 4 1/2 inches, width is 5 inches, and length is 3 3/4 inches is <em><u>5400 </u></em>

4 0

2 years ago

Read 2 more answers

Help me out i would appreciate it

Mariulka [41]

Step-by-step explanation:

find the area of the rectangle

then surface area=.......

then subtract by the volume of rectangle by the other one

7 0

2 years ago

PLEASE HELP!!! Maria is saving money so she can go to a professional football game. Maria has $25. She saves $5 a week. Graph a

Kruka [31]

Equation would be: Y = 25 + 5x
Where, x = number of weeks
So, when x = 1, Y = 25 + 5(1) = 25+5 = 30
When x = 2, Y = 25 + 5(2) = 25 + 10 = 35
x = 3, Y = 25 + 5(3) = 25 + 15 = 40

So, Mark the coordinates: (0, 25), (1, 30), (2, 35), (3, 40), (4, 45), (5, 50)...
And draw a line...Graph is done!

Hope this helps!

6 0

2 years ago

Help please I am not understand​

Help please I am not understand