please I need help this is important pls​

Answer:

C. 120 m²

Step-by-step explanation:

The surface area is equal to the area of 4 rectangles + area of 4 triangles + area of base.

Area of 4 rectangles:

4(5 × 4)

4(20) = 80

Area of 4 triangles:

4(3 × 4 × 1/2)

4(6) = 24

Area of base:

4² = 16

Add the areas.

16 + 24 + 80

= 120

The surface area of the composite solid is 120 m².

The surface area of this composite solid would be, 136 m². Hence, option D is true.

Used the formula for the surface area of the cuboid and the surface area of the 4 triangles,

The surface area of the cuboid = 2 (LW + LH + HW)

And, The surface area of the 4 triangles = 4 (1/2 × Base × Height)

Given that,

In a triangle,

Base = 4 m

Height = 3 m

And, In a Cuboid,

Length = 4 m

Width = 4 m

Height = 5 m

Hence, we get;

The surface area of the 4 triangles = 4 (1/2 × Base × Height)

= 4 (1/2 × 4 × 3)

= 4 × 6

= 24 m²

The surface area of the cuboid = 2 (LW + LH + HW)

= 2 (4 × 4 + 4 × 5 + 5 × 4)

= 2 (16 + 20 + 20)

= 112 m²

Therefore, The surface area of this composite solid would be,

24 m² + 112 m² = 136 m²

So, Option D is true.

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Answer:

1 1/8

Step-by-step explanation:

1/4 + 7/8

Make denominators equal.

2/8 + 7/8

Add the fractions.

9/8

Convert to a mixed fraction.

1 1/8

Answer:

1  1/8

Step-by-step explanation:

1/4 + 7/8

Get a common denominator

1/4 * 2/2 + 7/8

2/8 + 7/8

9/8

Change to a mixed number

8/8+ 1/8

1  1/8

Answer:

9 pounds of deluxe

42 pounds of regular

Step-by-step explanation:

given data

Deluxe coffee mix with regular coffee = 51

mix contains deluxe coffee = 9 pounds

Deluxe coffee costs ​$5

regular coffee costr = ​$3

solution

we consider here

deluxe coffee = x lbs

regular coffee = y lbs

and

x+ y ≥ 52

and mixture contains at least 9 pounds of deluxe coffee

so  x ≥ 9

and

cost equation will be

cost C = 5x + 3 y

deluxe costs more than regular

and here we want to use as possible as to minimize the cost

so least amount

x + y = 51

x  = 9

y = 51 - 9

y = 42

Answer:

11,800 different four letter permutations can be formed using four letters out of the first 12 in the alphabet

Step-by-step explanation:

Permutations formula:

The number of possible permutations of x elements from a set of n elements is given by the following formula:

[tex]P_{(n,x)} = \frac{n!}{(n-x)!}[/tex]

In this question:

Permutations of four letters from a set of 12 letters. So

[tex]P_{(12,4)} = \frac{12!}{(12-4)!} = 11800[/tex]

11,800 different four letter permutations can be formed using four letters out of the first 12 in the alphabet

Answer: it’s 11,880

not 11800

Answer:

4

Step-by-step explanation:

Since there are 4 columns of x and y values the answer is 4.

Answer:

How many points should appear in Kelsey’s graph   Option B

(B) 4

Step-by-step explanation:

Answer:

The x-intercepts as shown on this graph are: (-3,0), (1,0), and (3,0). The y-intercept as shown on this graph is: (0,2).

Step-by-step explanation:

The intercepts refer to where the function intersects with either the x-axis or y-axis. Since the line crosses the y-axis at (0,2), that's the y-intercept. The same thing applies to the x-intercepts. On this graph, it's easier to identify because the intercepts are marked with dots.

hope it helps uh.......

Answer:

D

Step-by-step explanation:

Answer:

Radius = 6.5cm

Diameter = 13cm

Step-by-step explanation:

The diameter is given (13)

Radius is half the diameter (13/2=6.5)

Answer:

Explanation

The straight line is drawn from the centre of a circle to a point on its circumference is called radius of the circle. The radius of a circle is half of its diameter.

The chord that passes through the centre of a circle is called diameter of circle. Diameter is also called the largest chord of any circle. The length of diameter of a circle is two times it's radius.

Hope this helps...

Good luck on your assignment...

Answer:

1. JG (Jim gets first prize, George gets second prize)

2. JH (Jim gets first prize, Helen gets second prize)

3. JM (Jim gets first prize, Maggie gets second prize)

4. GH (George gets first prize, Helen gets second prize)

5. GJ (George gets first prize, Jim gets second prize)

6. GM (George gets first prize, Maggie gets second prize)

7. MJ (Maggie gets first prize, Jim gets second prize)

8. MG (Maggie gets first prize, George gets second prize)

9. MH (Maggie gets first prize, Helen gets second prize)

Step-by-step explanation:

The question asks for the list of outcomes in the event "Not A". We are looking for the reverse or negative of Event A.

The above given list is the list of outcomes in the event where Helen DOES NOT get first prize.

Answer:

$80

Step-by-step explanation:

Let the number of hours required to make a mailbox = x

Let the number of hours required to make a toy = y

Each mailbox requires 1 hour of work from Carlo and 4 hours from Anita.

Each toy requires 1 hour of work from Carlo and 1 hour from Anita.

The table below summarizes the information for ease of understanding.

[tex]\left|\begin{array}{c|c|c|c}&$Mailbox(x)&$Toy(y)&$Maximum Number of Hours\\--&--&--&------------\\$Carlo&1&1&12\\$Anita&4&1&24\end{array}\right|[/tex]

We have the constraints:

[tex]x+y \leq 12\\4x+y \leq 24\\x \geq 0\\y \geq 0[/tex]

Each mailbox sells for $10 and each toy sells for $5.

Therefore, Revenue, R(x,y)=10x+5y

The given problem is to:

Maximize, R(x,y)=10x+5y

Subject to the constraints

[tex]x+y \leq 12\\4x+y \leq 24\\x \geq 0\\y \geq 0[/tex]

The graph is plotted and attached below.

From the graph, the feasible region are:

(0,0), (6,0), (4,8) and (0,12)

At (6,0), 10x+5y=10(6)+5(0)=60

At (4,8), 10(4)+5(8)=80

At (0,12), 10(0)+5(12)=60

The maximum revenue occurs when they use 4 hours on mailboxes and 8 hours on toys.

The maximum possible revenue is $80.

Answer:

Step-by-step explanation:

Hello!

*Full text*

A fisheries biologist has been studying horseshoe crabs. She has sampled 100 horseshoe crabs and recorded their weight (in kilograms) and width (in centimeters). The proposed regression equation is

weight = b + width * m

This model was fit to the data using the method of the least squares. The following results were obtained from statistical software.

(See attachment for output)

R2 = 0.423

A.) What is the regression equation for this example?

The estimate for the y-intercepts is b= 2.3013 and the estimate for the slope is m= 0.7963

In general, we can symbolize the estimated regression equation as ^Y= b + m*Xi. For this example you have to replace it with the calculated values of the regression coefficients to obtain the estimated regression equation:

^Y= 2.3013 + 0.7963Xi

B.) What is the explanatory, or predictor, variable in this study?

The explanatory or predictor variable is the variable that is suspected to have an effect over the response variable. In this example the predictor variable is:

X: Width of a horseshoe crab (cm)

C.) If the researcher wanted to test whether there is a statistically significant relationship between these two variables, what would the test statistic be? Calculate it from the table above.

To test if the regression is significant, the parameter of study will be the slope of the regression equation, symbolically: β. If the slope is equal to zero "β=0" then there is no linear regression between the response and explanatory variable. If the slope is different from zero "β≠0" then the regression is significant and the explanatory variable affects the response variable.

The hypotheses are:

H₀: β=0

H₁: β≠0

α: 0.05

[tex]t= \frac{m-\beta }{S_m} ~t_{n-2}[/tex]

[tex]t_{H_0}= \frac{0.7963-0}{0.0939}= 8.48[/tex]

The value of the statistic under the null hypothesis is t= 8.48

D.) What can we say about the p-value?

This test is two-tailed and so is the p-value, remember that the p-value is the probabulity of obtaining a value as extreme as the value of the statistic under the null hypothesis. The distribution for this test is a t with n-2= 100-2= 98 degrees of freedom. You can calculate the p-value as:

P(t₉₈≤-8.48) + P(t₉₈≥8.48)= P(t₉₈ ≤ -8.48) + (1 - P(t₉₈ < 8.48) ≅ 0.00001

E.) Ultimately, the reason that we find test statistics is so that we can compare them to a null distribution. For regression, that is a t-distribution based on the degrees of freedom. With 98 degrees of freedom (100-2), we can safely say that the critical t (or the confidence multiplier) is what?

As mentioned before, this test is two tailed, meaning that the rejection region is divided in two:

Critical values ±[tex]t_{n-2;1-\alpha /2}[/tex] = ± [tex]t_{98; 0.975}[/tex] = ± 1.984

This means that you'll reject the null hypothesis when the statistic is t ≤ -1.984 or if the statistic is t ≥ 1.984-

F.) Find the confidence interval for the slope.

Using a 95% confidence level, the interval for the slope is:

[m ± [tex]t_{n-2;1-\alpha /2}[/tex] Sm]

[0.7963 ± 1.984 * 0.0939]

[0.61; 0.98]

G.) Is there a statistically significant relationship? Answer with the test statistic and the confidence interval.

Yes, there is a significant relationship between the width and weight of the horseshoe crabs.

Using the critical value approach:

The calculated statistic is 8.48 and the critical value is ± 1.984, since the statistic is greater than the positive critical value, the decision is to reject the null hypothesis.

If you pay attention to the confidence interval, which was made at a confidence level complementary to the significance level of the hypothesis test, this interval [0.61; 0.98] doesn't include the "zero". Since the interval doesn't include the value of the parameter stated in the null hypothesis, you can conclude that this hypothesis is not true and therefore reject it.

I hope this helps!

Answer:

B. Use your compass to draw an arc at C

Step-by-step explanation:

General rules and ways to draw line AB and another line parallel to AB

Use a meter rule and draw a line.

Mark out your point AB in the line using your compare with specified dimensions.

Place your compass at A and draw an arc above the line.

Place your compass at B also and draw an arc above the line.

Where the both arc intersect name it C.

Then Use your compass to draw an arc at C.

Draw another arc of same dimension and equidistant to c.

Join both arc to give a parallel line with line AB

Answer: it’s c

Step-by-step explanation:

because I just got it wrong on a-pex

The required length of the line is given as 14.4 feet, as of the given conditions.

As given in the question, A kite is flying 12 ft off the ground. Its line is pulled taut and casts an 8 -ft shadow, to determine the length of the line.

In a right-angled triangle, its side, such as the hypotenuse, is perpendicular, and the base is Pythagorean triplets.

Here,
let the length of the line be x,
The scenario formed is right angle triangle,
Apply Pythagoras' theorem,
x² = 12² + 8²
x = √208
x = 14.4

Thus, the required length of the line is given as 14.4 feet, as of the given conditions.

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Answer:

Option D is correct.

1/4 completes the square.

Step-by-step explanation:

To complete the square for a quadratic function, we require a third term that will enable the solutions of the quadrstic equation to be 2 repeated roots.

For that to be so for the quadratic equation

ax² + bx + c = 0,

b² has to be equal to 4ac

For this question, x² - x + c

From b² = 4ac

c = (b²/4a)

a = 1

b = -1, b² = 1

c = ?

c = (1/4)

Hence, (1/4) is the number that must be added to the expression to complete the square.

Hope this Helps!!!

Answer: Left column x- axis

Right column : Tournament round

Left column: y-axis.

Right column: number of teams remaining

Step-by-step explanation:

You expect the y -value, teams remaining to decrease as you go from the first round to the last round in the x-values.

After the first round only 32 teams will left.

After the second round 16 teams will left.

After the third round 8 teams will left.

After the fourth round only 4 teams will left.

After the fifth round only 3 teams will left.

After the sixth round only 1 team will left.

If x and y are two variables in an algebraic equation and every value of x is linked with any other value of y, then 'y' value is said to be a function of x value known as an independent variable, and 'y' value is known as a dependent variable.

An exponential function is a mathematical function in the form f(x) = [tex]a^{x}[/tex] where x is a variable, and a is a constant called the base of the function.

According to the given question

We have an exponential function

[tex]f(x) = 64(\frac{1}{2} )^{x}[/tex]

And y-axis  represents the teams remaining and x axis represents the tournaments round

Since, here the values of x are independent variables and values of y are dependent variables.

Now for the

Tournament round 1 ,

y = f(1) = [tex]64(\frac{1}{2} )=32[/tex]

⇒ 32 teams are remaining

Tournament round 2

[tex]y = f(2) = 64(\frac{1}{2}) ^{2}[/tex]

⇒ y = 16, only 16 teams are remaining

For round 3

[tex]y = f(3) = 64(\frac{1}{2}) ^{3} =8[/tex]

For round 4

[tex]y = f(4) = 64(\frac{1}{2} )^{4}= 4[/tex]

⇒ Only 4 teams are remaining

For round 5

[tex]y = f(5) = 64(\frac{1}{2} )^{5} = 2[/tex]

⇒ only 2 teams are remaining

For round 6

[tex]y = f(6) = 64(\frac{1}{2}) ^{6}=1[/tex]

⇒ only one team is remaining

By using these parameters we will plot a graph for tournament rounds .

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Answer:

4/11

Step-by-step explanation:

The probability of winning a new TV is the number of times you will win a TV over the total number of times you try to win a TV. In this case, the odds of winning a new TV are 4/7, or 4 wins every 7 loses. (Odds are probability of success to failure) Therefore, there are 4 wins for every 4 + 7 raffles, or 4/11.

Answer:

Critical value: b. 2.33

As the test statistic z=7.17 is greater than the critical value, it falls in the rejection region.

The null hypothesis is rejected.

There is enough evidence to support the claim that the proportion of women who think sexual harassment is a major problem in the American workplace is significantly higher than the proportion of men.

Step-by-step explanation:

This is a hypothesis test for the difference between proportions.

The claim is that the proportion of women who think sexual harassment is a major problem in the American workplace is significantly higher than the proportion of men.

Then, the null and alternative hypothesis are:

[tex]H_0: \pi_1-\pi_2=0\\\\H_a:\pi_1-\pi_2> 0[/tex]

The significance level is 0.01.

The sample 1 (women), of size n1=150 has a proportion of p1=0.62.

The sample 2 (men), of size n2=200 has a proportion of p2=0.24.

The difference between proportions is (p1-p2)=0.38.

[tex]p_d=p_1-p_2=0.62-0.24=0.38[/tex]

The pooled proportion, needed to calculate the standard error, is:

[tex]p=\dfrac{X_1+X_2}{n_1+n_2}=\dfrac{93+48}{150+200}=\dfrac{141}{350}=0.403[/tex]

The estimated standard error of the difference between means is computed using the formula:

[tex]s_{p1-p2}=\sqrt{\dfrac{p(1-p)}{n_1}+\dfrac{p(1-p)}{n_2}}=\sqrt{\dfrac{0.403*0.597}{150}+\dfrac{0.403*0.597}{200}}\\\\\\s_{p1-p2}=\sqrt{0.001604+0.001203}=\sqrt{0.002807}=0.053[/tex]

Then, we can calculate the z-statistic as:

[tex]z=\dfrac{p_d-(\pi_1-\pi_2)}{s_{p1-p2}}=\dfrac{0.38-0}{0.053}=\dfrac{0.38}{0.053}=7.17[/tex]

The critical value for a right-tailed test with a signficance level of 0.01 is zc=2.33 (see picture attached).

As the test statistic z=7.17 is greater than the critical value, it falls in the rejection region.

The null hypothesis is rejected.

There is enough evidence to support the claim that the proportion of women who think sexual harassment is a major problem in the American workplace is significantly higher than the proportion of men.

Answer:

4% is a statistic and 1% is a parameter

Step-by-step explanation:

First, let's remember the differences between parameters and statistics:

Parameters are values that describe data of the entire population.

Statistics are values that describe data from a sample.

The value of 1% refers to "all of the parts", which is the population of over 1 million parts, thus 1% is a parameter.

The value of 4% refers to the "100 selected", which is the sample of 100 parts, thus 4% is a statistic.

Therefore, 4% is a statistic and 1% is a parameter.

Answer:

40 miles per hr.

Step-by-step explanation:

alll u have to do is divide the number of miles by the hrs.

ex.80/2=40

140/3.5=40

200/8=40

300/7.5=40

Answer:

x = 5/2

x = 2 1/2

x = 2.5

Step-by-step explanation:

3x - 1 - (x + 3) = 1

3x - 1 - x - 3 = 1

2x - 1 - 3 = 1

2x - 4 = 1

2x = 1 + 4

2x + 5

2x = 5

x = 5/2 → 2 1/2 → 2.5 ( can be written in any of these forms depending on what you need to do)

Hope this helped! :)

Answer:

Step-by-step explanation:

3x−1−(x+3)=1

First remove the bracket

That's

3x - 1 - x - 3 = 1

Group the constants at the right side of the equation

That's

3x - x = 1 + 1 + 3

Simplify

We have

2x = 5

Divide both sides by 2

That's

2x / 2 = 5/2

Hope this helps you

Answer:

True

Step-by-step explanation:

Perpendicular lines are lines whose angles are 90 degrees

Lines that are perpendicular have slopes that multiply to -1

-1* 1 = -1

Lines that are parallel have the same slope

We have 2 lines that are parallel with 1 and 1

And 2 lines that are parallel with -1 and -1

These 2 sets of lines are perpendicular to each other so they make 90 degree angles

Answer:

it is true

Step-by-step explanation:

because perpendicular lines are 90 degrees and the slope can be coorinated as 1,-11 and -1 respectively.

hope this helps

plz mark brainliest if answer is correct

Answer:

192 m^2.

Step-by-step explanation:

We can split this up into 3 rectangles:

Area of the bottom rectangle = 27 * (9-3)

= 27 * 6 = 162 m^2.

Area of rectangle on the left = (18-6)*2

= 24 m^2

Area of small rectangle on the right = 3*2

= 6 m^2

Total area = 162+24+6

192 m^2.

Answer:

31 units

Step-by-step explanation:

I just did it

The length of segment AD must be 31 units for ABCD to be a parallelogram.

A rectangle is a two dimension figure with 4 sides, 4 corners and 4 right angles. The opposite sides of the rectangle are equal and parallel to each other.

Now, When the figure is a parallelogram, opposite sides have the same measure:

That is,

⇒ AD = BC

Plug the given values we get;

⇒ 3x +7 = 5x -9

⇒ 16 = 2x

⇒  8 = x

Hence, Use this value of x in the expression for AD to find its required length:

 AD = 3(8) +7 = 24 +7

 AD = 31 . . . . units

Thus, The length of segment AD must be 31 units for ABCD to be a parallelogram.

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Answer:

1

Step-by-step explanation:

We will use polynomial remainder theorem or little Bézout's theorem. It states that reminder p(x) divided by (x - a) is p(a). In our case (a = 3) it is p(3) = 1

Answer:

  Rn ≈ 0.6345

  Ln ≈ 0.7595

Step-by-step explanation:

The interval from -1 to 2 has a width of (2 -(-1)) = 3. Dividing that into 4 equal intervals means each of those smaller intervals has width 3/4.

It can be useful to use a spreadsheet or graphing calculator to evaluate the function at all of the points that define these intervals:

  x = -1, -.25, 0.50, 1.25, 2

Of course, the spreadsheet can easily compute the sum of products for you.

__

The approximation using right end-points will be the sum of products of the interval width (3/4) and the function value at the right end-points:

  Rn = (3/4)f(-0.25) +(3/4)f(0.50) +(3/4)f(1.25) +(3/4)f(2)

  Rn ≈ 0.6345

__

The approximation using left end-points will be the sum of products of the interval width (3/4) and the function value at the left end-points:

  Ln = (3/4)f(-1) +(3/4)f(-0.25) +(3/4)f(0.50) +(3/4)f(1.25)

  Ln ≈ 0.7595

_____

It is usually convenient to factor out the interval width, so only one multiplication needs to be done: (interval width)(sum of function values).

Answer:

2 ft/s

Step-by-step explanation:

The lamppost is 24 ft. tall, and the man is 6 ft. tall. So, we will use a proportion to find the shadow.

Let s is the length of the base of the lamppost to the shadow while x is the length of the base of the lamppost to the man, so the length of the shadow is s - x.

Using triangular ratio, we have;

24/6 = s/(s - x)

4 = s/(s - x)

We cross multiply and distribute to get;

4s - 4x = s

4s - s = 4x

3s = 4x

s = 4x/3

Taking the derivative of both sides according to time, we have;

ds/dt = (4/3)dx/dt

Now, dx/dt is given as 6 ft/s

So;

ds/dt = (4/3) × 6

ds/dt = 8 ft/s

For us to find the rate of length of the shadow according to time, we recall that the shadow = s - x, so we will just take the derivative of each and subtract. Thus;

d(s - x)/dt = ds/dt - dx/dt

Plugging in the relevant values, we have;

ds/dt - dx/dt = 8 - 6 = 2 ft/s

Answer:

An inverse variation is something of the shape:

y = k/x.

Knowing that the point (5, 10) is included in this equation, we can obtain the value of k.

10 = k/5.

10*5 = k

k = 50

Then our inverse variation is:

y = 50/x.

Now we can give any value of x in order to find another point that is included in the variation, for example, if x = 5

y(5) = 50/5 = 10

then the point (5, 10) does also belong to the inverse variation.

if x = 50

y(50) = 50/50 = 1.

then the point (50, 1) does also belong to the inverse variation.

Answer:

x=-1

Step-by-step explanation:

8/x+2=2/x-4

8/x=2/x-6

8=2-6x

6=-6x

-1=x

Answer:

x=6

Step-by-step explanation:

8/x+2=2/x-4

Using cross products

8*(x-4) = 2 (x+2)

Distribute

8x - 32 = 2x+4

Subtract 2x

8x-2x -32 = 2x-2x+4

6x-32 = 4

Add 32

6x-32+32 = 4+32

6x = 36

Divide by 6

6x/6 = 36/6

x = 6

Answer:

c. dividing is the inverse of multiplying because it doesn't really relate the equation like the others do.