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2 years ago

Explain the relationship between variance and standard deviation. Can either of these measures be negative? Explain.

Mathematics

2 answers:

koban [17]2 years ago

7 0

Answer:

We can define the standard deviation as the square root of the variance.

The unit for standard deviation and mean are same. But the variance is expressed in square units.

The variance cannot be negative, because then, you cannot find the square root of it.

Similarly, under no circumstances, the standard deviation can be negative. The standard deviation formula is calculated by using squares of the numbers, and square of a number cannot be negative.

jarptica [38.1K]2 years ago

6 0

Standard deviation is the square root of variance. Variance is always a non-negative number, since you can't take the square root of a negative number. So neither can be negative

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two ships leave a port at the same time. the first ship sails on a bearing of 55° at 12 knots (natural miles per hour) and the s

Korvikt [17]

Answer:

37.59 nautical miles

Explanation:

Distance = Speed x Time

The speed of the first ship = 12 knots

Thus, the distance covered after 1.5 hours

$\begin{gathered} =12\times1.5 \\ =18\text{ miles} \end{gathered}$

The speed of the second ship = 22 knots

Thus, the distance covered after 1.5 hours

$\begin{gathered} =22\times1.5 \\ =33\text{ miles} \end{gathered}$

The diagram representing the ship's path is drawn and attached below:

The angle at port = 90 degrees.

The triangle is a right triangle.

Using Pythagorean Theorem:

$\begin{gathered} c^2=a^2+b^2 \\ c^2=18^2+33^2 \\ c^2=324+1089 \\ c^2=1413 \\ c=\sqrt[]{1413} \\ c=37.59\text{ miles} \end{gathered}$

The two ships are 37.59 nautical miles apart after 1.5 hours.

8 0

1 year ago

MAJOR HELP!

Feliz [49]

Answer:

The radius of the cone is 21 units

The volume of the cone is 9702 units³

Step-by-step explanation:

* Lets revise the area of the circle and the volume of the cone

- The base if the cone is a circle

- The area of the circle is πr², where r is the radius of the circle

∵ The area of the base of the cone = 1386 units²

∵ The area of the base = πr²

∵ π = 22/7

∴ 1386 = 22/7 (r²) ⇒ multiply each side by 7

∴ 9702 = 22 r² ⇒ divide both sides by 22

∴ 441 = r² ⇒ take √ for both sides

∴ 21 = r

* The radius of the cone is 21 units

- The volume of the cone = 1/3 πr²h , where h is the height of the cone

∵ The cone's height is equal to the radius of its base

∴ h = r

∵ The volume of the cone = 1/3 πr²h

∴ The volume of the cone = 1/3 πr²(r) = 1/3 πr³

∵ r = 21 units

∴ The volume of the cone = 1/3 (22/7) (21)³

∴ The volume of the cone = 9702 unit³

* The volume of the cone is 9702 units³

3 0

3 years ago

Please help! Thanks alot

Rina8888 [55]

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6 0

2 years ago

Read 2 more answers

Write and solve a system of equations: Vanessa and Geneva worked together to buy a pair of tickets ($240 total) to the Green Day

Goshia [24]

Answer:

The systems of equation are $\left \{ {{v+g=21} \atop {10v+12g=240}} \right.$ .

Vanessa worked for 6 hrs and Geneva worked for 15 hrs to earn exactly $240.

Step-by-step explanation:

Let the number of hours worked by Vanessa be 'v'.

Let the number of hours worked by Geneva be 'g'.

Given:

Total number of hours worked = 21 hours

So we can say that;

Total number of hours worked is equal to sum of number of hours worked by Vanessa and number of hours worked by Geneva.

framing in equation form we get;

$v+g=21$ ⇒ equation 1

Also given:

per hour earnings of Vanessa = $10

per hour earning of Geneva = $12

Total they need to earn = $240

So we can say that;

Total they need to earn would be equal to sum of per hour earnings of Vanessa multiplied by number of hours worked by Vanessa and per hour earning of Geneva multiplied by number of hours worked by Geneva.

framing in equation form we get;

$10v+12g =240$ ⇒ equation 2