Can you help me solve it it driving me bonkers

A rectangular pen is built with one side against a barn. if 300 m of fencing are used for the other three sides of the pen, wha

shutvik [7]

Let w= the length of the side perpendicular to the barn
300-2w= length of the side parallel to the barn
A=w(300-2w)
A=-2w^2+300w
The formula for the w-value of maximum is:
=-b/2a
thus our value will be:
300/4
=75
and
300-2(75)
=150
thus the dimensions to maximize the area is 75 by 150

6 0

4 years ago

The random variable x represents the number of computers that families have along with the corresponding probabilities. Find the

Elena L [17]

Answer:

The correct option is (d).

Step-by-step explanation:

The complete question is:

The random variable x represents the number of computers that families have along with the corresponding probabilities. Use the probability distribution table below to find the mean and standard deviation for the random variable x.

x : 0 1 2 3 4

p (x) : 0.49 0.05 0.32 0.07 0.07

(a) The mean is 1.39 The standard deviation is 0.80

(b) The mean is 1.39 The standard deviation is 0.64

(c)The mean is 1.18 The standard deviation is 0.64

(d) The mean is 1.18 The standard deviation is 1.30

Solution:

The formula to compute the mean is:

$\text{Mean}=\sum x\cdot p(x)$

Compute the mean as follows:

$\text{Mean}=\sum x\cdot p(x)$

$=(0\times 0.49)+(1\times 0.05)+(2\times 0.32)+(3\times 0.07)+(4\times 0.07)\\\\=0+0.05+0.64+0.21+0.28\\\\=1.18$

The mean of the random variable x is 1.18.

The formula to compute variance is:

$\text{Variance}=E(X^{2})-[E(X)]^{2}$

Compute the value of E (X²) as follows:

$E(X^{2})=\sum x^{2}\cdot p(x)$

$=(0^{2}\times 0.49)+(1^{2}\times 0.05)+(2^{2}\times 0.32)+(3^{2}\times 0.07)+(4^{2}\times 0.07)\\\\=0+0.05+1.28+0.63+1.12\\\\=3.08$

Compute the variance as follows:

$\text{Variance}=E(X^{2})-[E(X)]^{2}$

$=3.08-(1.18)^{2}\\\\=1.6876$

Then the standard deviation is:

$\text{Standard deviation}=\sqrt{\text{Variance}}$

$=\sqrt{1.6876}\\\\=1.2990766\\\\\approx 1.30$

Thus, the mean and standard deviation for the random variable x are 1.18 and 1.30 respectively.

The correct option is (d).

3 0

3 years ago

Marilyn knows that she needs $45,000 for a down payment on a house. She found an investment that earns 3.15% interest compoundin

laila [671]

She should save $38,450.39.

The formula for the amount of money in an interest-bearing account that is compounded is

$A=p(1+\frac{r}{n})^{nt}$

where A is the total amount in the account, p is the amount of principal invested, r is the interest rate as a decimal number, n is the number of times per year interest is compounded, and t is the number of years. Using our information we have:

$45000=p(1+\frac{0.0315}{12})^{12\times5}
\\
\\45000=p(1.002625)^{60}$

Divide both sides:
$\frac{45000}{1.002625^{60}}=\frac{p(1.002625)^{60}}{1.002625^{60}}
\\
\\38450.39=p$

5 0

3 years ago

What's 1/10 at four in the number 42,000

Serhud [2]

42,000 split into 10 is 4,200
if you meant 4 of those then it would be 16,800

6 0

3 years ago

What's the area of the above figure, which has sides of length 6and 8

Iteru [2.4K]

The answer appears to be 48

3 0

4 years ago

Read 2 more answers