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3 years ago

Calculate the standard deviation. Variance = 107.76. Mean = 34.2

Mathematics

1 answer:

Llana [10]3 years ago

8 0

Answer:

The standard deviation is 10.38

Step-by-step explanation:

Given;

Variance, v = 107.76

mean, x = 34.2

The standard deviation is given by;

standard deviation = √variance

standard deviation = √107.76

standard deviation = 10.381

standard deviation = 10.38 (two decimal places)

Therefore, the standard deviation is 10.38

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John has 12 pounds of dog food and is going to separate it into 3/4 pound portions. How many portions of dog food will he have?

NNADVOKAT [17]

16 portions

explanation:

12 / 3/4

= 12 * 4/3

= 4*4 = 16

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2 years ago

There are 50 apple trees in an orchard. Each tree produces 800 apples. For each additional tree planted in the orchard, the outp

Mariana [72]

Answer:

15
42,250

Step-by-step explanation:

The given function is,

$P=40000+300x-10x^2$

where,

P = the total production of apples,

x = the number of trees added.

As the quadratic function has a negative leading coefficient, so it will open downward and at the vertex the value of function is maximum.

The vertex will be at $\left(-\dfrac{b}{2a},-f\left(\dfrac{b}{2a}\right )\right)$

The value of the function will be maximum at,

$x=-\dfrac{b}{2a}$

Putting the values,

$x=-\dfrac{300}{2\times (-10)}=\dfrac{300}{2\times 10}=\dfrac{300}{20}=15$

So at x=15 or for 15 number of trees the production will be ,maximum.

Putting x=15 in f(x) will yield the maximum production of apples.

$P=40000+300(15)-10(15)^2=42,250$

4 0

3 years ago

The perimeter of a rectangular swimming pool is 160 feet . The length of the swimming pool is four times its width. Find the dim

Murrr4er [49]

Formula for Perimeter of Rectangle:

P = 2(L + W)

Plug in 160:

160 = 2(L + W)

L = 4W
So we can plug in '4W' for 'L' in the first equation.
160 = 2(L + W)

160 = 2(4W + W)

Combine like terms:

160 = 2(5W)

160 = 10W

Divide 10 to both sides:

W = 16

Now we can plug this back into any of the two equations to find the length.

L = 4W

L = 4(16)

L = 64

So the width is 16, and the length is 64.

6 0

3 years ago

Read 2 more answers

If it takes 6 hours for a plane to travel 720km with a tail wind and 8 hours to make the return trip with a head wind. Find the

denis-greek [22]

The speed of wind and plane are 105 kmph and 15 kmph respectively.

Solution:

Given, it takes 6 hours for a plane to travel 720 km with a tail wind and 8 hours to make the return trip with a head wind.

We have to find the air speed of the plane and speed of the wind.

Now, let the speed wind be "a" and speed of aeroplane be "b"

And, we know that, distance = speed x time.

$\text { Now, at tail wind } \rightarrow 720=(a+b) \times 6 \rightarrow a+b=\frac{720}{6} \rightarrow a+b=120 \rightarrow(1)$

Now at head wind → $720=(a-b) \times 8 \rightarrow a-b=\frac{720}{8} \rightarrow a-b=90 \rightarrow(2)$

So, solve (1) and (2) by addition

2a = 210

a = 105

substitute a value in (1) ⇒ 105 + b = 120

⇒ b = 120 – 105 ⇒ b = 15.

Here, relative speed of plane during tail wind is 120 kmph and during head wind is 90 kmph.

Hence, speed of wind and plane are 105 kmph and 15 kmph respectively.

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3 years ago

Jada lives in a city that has an area of 344.6 square miles. Her friend lives in a town that is 1/10th that size. What is the ar

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34.46 sqare miles 344.6 times 0.1 one tenth the size braniest please

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