(-19, -12), (-9, -15)

Katrina buys a 42-ft roll of fencing to make a rectangular play area for her dogs.

vekshin1

Answer:

(a) $l = -w + 21$

(b) Domain: $0$ (See attachment for graph)

(c) $f(w) = -w + 21$

Step-by-step explanation:

Given

$2(l + w) = 42$

$l = length$

$w = width$

Solving (a): A function; l in terms of w

All we need to do is make l the subject in $2(l + w) = 42$

Divide through by 2

$l + w = 21$

Subtract w from both sides

$l + w - w = 21 - w$

$l = 21 - w$

Reorder

$l = -w + 21$

Solving (b): The graph

In (a), we have:

$l = -w + 21$

Since l and w are the dimensions of the fence, they can't be less than 1

So, the domain of the function can be $0$

--------------------------------------------------------------------------------------------------

To check this

When $w = 1$

$l = -1 + 21$

$l = 20$

$(w,l) = (1,20)$

When $w = 20$

$l = -20 + 21$

$l = 1$

$(w,l)= (20,1)$

--------------------------------------------------------------------------------------------------

See attachment for graph

Solving (c): Write l as a function $f(w)$

In (a), we have:

$l = -w + 21$

Writing l as a function, we have:

$l = f(w)$

Substitute $f(w)$ for l in $l = -w + 21$

$l = -w + 21$ becomes

$f(w) = -w + 21$

5 0

3 years ago

Based on information from Harper’s Index, 37% of adult Americans believe in Extraterrestrials. Out of a random sample of 100 adu

san4es73 [151]

Answer:

z(s) is in the rejection zone , therefore we reject H₀

We have enough evidence to claim the proportion of individuals who attended college and believe in extraterrestrials is bigger than 37%

Step-by-step explanation:

We have a prortion test.

P₀ = 37 % P₀ = 0,37

sample size = n = 100

P sample proportion = P = 47 % P = 0,47

confidence interval 95 %

α = 0,05

One tail-test (right tail) our case is to show if sample give enough information to determine if proportion of individual who attended college is higher than the proportion found by Harper´s index.

1.-Hypothesis:

H₀ null hypothesis P₀ = 0,37

Hₐ alternative hypothesis P₀ > 0,37

2.-Confidence interval 95 %

α = 0,05 and z(c) = 1.64

3.-Compute of z(s)

z(s) = [ P - P₀ ] /√(P₀Q₀/n) ]

z(s) = [ ( 0,47 - 0,37 ) / √0.37*0,63/100

z(s) = 0,1 /√0,2331/100 ⇒ z(s) = 0,1 /0,048

z(s) = 2.08

4.-Compare z(s) and z(c)

z(s) > z(c) 2.08 > 1.64

5.-Decision:

z(s) is in the rejection zone , therefore we reject H₀

We have enough evidence to claim the proportion of individuals who attended college and believe in extraterrestrials is bigger than 37%

5 0

4 years ago

234.2 in expanded form

avanturin [10]

Answer:

Expanded Notation Form:

234.2

=

200

+

30

+

4

+

0.2

Expanded Factors Form:

234.2

=

2 ×

100

+

3 ×

10

+

4 ×

1

+

2 ×

0.1

Expanded Exponential Form:

234.2 =

2 × 102

+

3 × 101

+

4 × 100

+

2 × 10-1

Word Form:

234.2 =

two hundred thirty-four and two tenths

8 0

3 years ago

What is 5/8 1/2 2/3 2/5 from least to greatest

S_A_V [24]

Answer:2/5, 1/2, 5/8, 2/3

Step-by-step explanation:

im in 10th grade i thin k i know my fractions

4 0

3 years ago

5m - 3n = 19; m - 6n = -7 /pls. help me solve this linear equation with two variables.

Allisa [31]

Answer:

m = 5, n = 2

Step-by-step explanation:

$5m - 3 n = 19\\m - 6n = - 7 \ => m = -7 + 6n\\\\Substitute \ m \ in \ 5m - 3n = 19\\\\5(-7 + 6n) - 3n = 19\\-35 + 30n -3n = 19\\27n = 19 + 35 \\27n = 54 \\n = 2\\\\Substitute \ n = 2 \ in \ m = -7 + 6n\\\\m = -7 + (6 \times 2) = -7 + 12 = 5$

5 0

3 years ago