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3 years ago

Need help please help

Mathematics

1 answer:

Art [367]3 years ago

8 0

Answer:

Step-by-step explanation:

$\frac{\sqrt{72}-21 }{27} =\frac{6\sqrt{2} -21}{27} =\frac{2\sqrt{2}-7 }{9}$

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Maria sets a goal of jogging 17.5miles this week. She plans on running 2.75 miles each day for 7 days . If she follows her plan

vovangra [49]

Yes, he will get 19.25 miles.

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2 years ago

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Could some one plz help me with this question

zhuklara [117]

Answer:

Step-by-step explanation:

The formula for this type of interest is $A=P(1+\frac{r}{n})^{nt}$ , where A is the total amount, P is the initial investment, x is the interest rate, n is the amount of times that the investment is compounded a year, and t is the amount of years. Plugging in the numbers given, you get:

$A=1800(1+\frac{0.025}{2})^{2\cdot 12}=$

$1800(1.0125)^{24}\approx 2425.23$

Now, she invests this into a new account, and you can set up the following equation:

$A=2425.23(1+\frac{0.04}{12})^{12\cdot 7}=$

$2425.23(1.0033333)^{84}\approx 3207.40$ , or option A.

Hope this helps!

3 0

3 years ago

If f(x)=x2-2x and g(x) =6x+4, for whichvalue of x dose (f+g)(x)=0

Juliette [100K]

Answer:

The value of x that makes the equation equal to 0 is -2.

Step-by-step explanation:

In order to find this, we first must create the composite function using the designated operation. The operation is addition, so we just add them together.

f(x) + g(x) = (f+g)(x)

(x^2 - 2x) + (6x + 4) = (f+g)(x)

x^2 + 4x + 4 = (f+g)(x)

Now, in order to find when this is equal to 0, we need to factor.

x^2 + 4x + 4 = 0

(x + 2)(x + 2) = 0

When it is fully factored, we can set each parenthesis equal to 0 in order to find the value. Since the parenthesis are exactly the same, we only have to do this once.

x + 2 = 0

x = -2

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2 years ago

How many feet aré in 280 yards

mars1129 [50]

280 yards are equal to 840 feet

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2 years ago

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An certain brand of upright freezer is available in three different rated capacities: 16 ft3, 18 ft3, and 20 ft3. Let X = the ra

ruslelena [56]

Answer:

$E(X)=16\cdot 0.3+18\cdot 0.1+20\cdot 0.6=18.6$

$E(X^2)=16^2\cdot 0.3+18^2\cdot 0.1+20^2\cdot 0.6=349.2$

$V(X) = E(X^2)-[E(X)]^2=349.2-(18.6)^2=3.24$

The expected price paid by the next customer to buy a freezer is $466

Step-by-step explanation:

From the information given we know the probability mass function (pmf) of random variable X.

$\left|\begin{array}{c|ccc}x&16&18&20\\p(x)&0.3&0.1&0.6\end{array}\right|$

Point a:

The Expected value or the mean value of X with set of possible values D, denoted by E(X) or μ is

$E(X) = $\sum_{x\in D} x\cdot p(x)$

Therefore

$E(X)=16\cdot 0.3+18\cdot 0.1+20\cdot 0.6=18.6$

If the random variable X has a set of possible values D and a probability mass function, then the expected value of any function h(X), denoted by E[h(X)] is computed by

$E[h(X)] = $\sum_{D} h(x)\cdot p(x)$

So $h(X) = X^2$ and

$E[h(X)] = $\sum_{D} h(x)\cdot p(x)\\E[X^2]=$\sum_{D}x^2\cdot p(x)\\ E(X^2)=16^2\cdot 0.3+18^2\cdot 0.1+20^2\cdot 0.6\\E(X^2)=349.2$

The variance of X, denoted by V(X), is

$V(X) = $\sum_{D}E[(X-\mu)^2]=E(X^2)-[E(X)]^2$

Therefore

$V(X) = E(X^2)-[E(X)]^2\\V(X)=349.2-(18.6)^2\\V(X)=3.24$

Point b:

We know that the price of a freezer having capacity X is 60X − 650, to find the expected price paid by the next customer to buy a freezer you need to:

From the rules of expected value this proposition is true:

$E(aX+b)=a\cdot E(x)+b$

We have a = 60, b = -650, and E(X) = 18.6. Therefore

The expected price paid by the next customer is

$60\cdot E(X)-650=60\cdot 18.6-650=466$

4 0

3 years ago