How do I solve this problem?

Answer:

[tex]b_1=\left(\begin{array}{ccc}-3\\3\end{array}\right),b_2=\left(\begin{array}{ccc}-\dfrac{65}{11}\\\\-\dfrac{19}{11}\end{array}\right)[/tex]

Step-by-step explanation:

Given matrix A and AB below:

[tex]A=\left(\begin{array}{ccc}1&-4\\-4&5\end{array}\right)\\\\\\ AB=\left(\begin{array}{ccc}-10&1&9\\7&-15&8\end{array}\right)[/tex]

For the product AB to be a 2 X 3 matrix, B must be a 2 X 3 matrix.

Let matrix B be defined as follows

[tex]B=\left[\begin{array}{ccc}a&c&e\\b&d&f\end{array}\right][/tex]

Therefore:

[tex]\left(\begin{array}{ccc}1&-4\\-4&5\end{array}\right)\left(\begin{array}{ccc}a&c&e\\b&d&f\end{array}\right)=\left(\begin{array}{ccc}-10&1&9\\7&-15&8\end{array}\right)[/tex]

This results in the equations

Solving the first two equations simultaneously

a-4b=-10  (a=-10+4b)

-4a+5b=7

Substitution of [tex]a=-10+4b[/tex] into the second equation

[tex]-4(-10+4b)+5b=7\\40-16b+5b=7\\-11b=-33\\b=3[/tex]

Recall that  [tex]a=-10+4b[/tex]

[tex]a=-10+4(3)=-10+7\\a=-3[/tex]

Solving the other two equations

c-4d=1 (c=1+4d)

-4c+5d=-15

Substitution of c=1+4d into the second equation

[tex]-4(1+4d)+5d=-15\\-4-16d+5d=15\\-11d=19\\d=-\dfrac{19}{11}\\ Recall: c=1+4d\\c=1+4(-\frac{19}{11})\\c=-\dfrac{65}{11}[/tex]

Therefore, we have:

[tex]a=-3, b=3, c=-\dfrac{65}{11}, d=-\dfrac{19}{11}[/tex]

Thus:

[tex]b_1=\left(\begin{array}{ccc}-3\\3\end{array}\right)\\\\\\b_2=\left(\begin{array}{ccc}-\dfrac{65}{11}\\\\-\dfrac{19}{11}\end{array}\right)[/tex]

Answer:

option c

Step-by-step explanation:

it is said that a computer repairman makes 25 dollars per hour

this column shows the right amount of money he earns per hour

Complete Question

The proportion of all students at this college who use drugs is a_____and the proportion of students who use drugs in your dorm is a _____ .

Options

Answer:

b. parameter; statistic

Step-by-step explanation:

A parameter is a summary of data for an entire population.

Statistic, on the other hand, summarizes data for a sample of the population.

The proportion of all students at this college who use drugs is a parameter and the proportion of students who use drugs in your dorm is a sample.

The correct option is B

Answer:

Step-by-step explanation:

Hello!

You have to determine the sample size to take to estimate the population proportion of Democrats among registered voters in Texas for a 96% interval with a margin of error of 0.01 and sample proportion p'= 0.28

The interval for the population proportion is

p' ± [tex]Z_{1-\alpha /2}[/tex]*[tex]\sqrt{\frac{p'(1-p')}{n} }[/tex]

The margin of error of the interval is:

d= [tex]Z_{1-\alpha /2}[/tex]*[tex]\sqrt{\frac{p'(1-p')}{n} }[/tex]

[tex]\frac{d}{Z_{1-\alpha /2}}= \sqrt{\frac{p'(1-p')}{n} }\\(\frac{d}{Z_{1-\alpha /2}} )^2= \frac{p'(1-p)}{n} \\n*(\frac{d}{Z_{1-\alpha /2}} )^2= p'(1-p)\\n= p'(1-p)*(\frac{Z_{1-\alpha /2}}{d} )^2\\[/tex]

[tex]Z_{1-\alpha /2}= Z_{0.98}= 2.054[/tex]

[tex]n= 0.28*(1-0.28)*(\frac{2.054}{0.01} )^2= 8505.33[/tex]

n= 8506 voters

I hope this helps!

Answer:

You count the amount in each section, add them all together and divide by the total amount of variables used to find the mean. for example, if you had the numbers 3, 5, 8, and 4, the mean would be (3+5+8+4)= 5

Step-by-step explanation:

Answer:

Option B is correct = [tex]0.3 \times 81[/tex]

Step-by-step explanation:

The complete question is: Which of the following options have the same value as 30% of 81?

Group of choices is:

(A) [tex]\frac{30}{100}\times 81 \times 100[/tex]

(B) [tex]0.3 \times 81[/tex]

(C) [tex]0.03 \times 81[/tex]

(D) [tex]\frac{3}{10}\times 81 \times 10[/tex]

(E) [tex]30 \times 81[/tex]

Now, the expression given to us is 30% of 81.

Simplifying the above expression we get;

   30% of 81  =  [tex]\frac{30}{100} \times 81[/tex]

                     =  [tex]\frac{3}{10} \times 81[/tex]  =  [tex]0.3 \times 81[/tex]

Now, we will solve each of the given options and then see which option matches with our calculation.

Option (A) is given;

[tex]\frac{30}{100}\times 81 \times 100[/tex]  =  [tex]30 \times 81[/tex]

This doesn't match with our answer, so this option is not correct.

Option (B) is given;

[tex]0.3 \times 81[/tex]  

This matches with our answer, so this option is correct.

Option (C) is given;

[tex]0.03 \times 81[/tex]  

This doesn't match with our answer, so this option is not correct.

Option (D) is given;

[tex]\frac{3}{10}\times 81 \times 10[/tex]  =  [tex]3 \times 81[/tex]

This doesn't match with our answer, so this option is not correct.

Option (E) is given;

[tex]30 \times 81[/tex]  

This doesn't match with our answer, so this option is not correct.

Answer:

1.2 metres

Step-by-step explanation:

1 metre = 100cm

so 120cm has 120 cm * 1 m/ 100cm = 1.2 m

Answer:

The smallest square number  that can be written using five different  Roman numerals is 10,000.

The result of the number divided by 24 is [tex]416 \dfrac{2}{3}[/tex]

Step-by-step explanation:

The lowest digit which can be written using five different Roman numerals is 10,000.

Therefore, the smallest square number must be greater than or equal to 10,000.

[tex]\sqrt{10,000} =100[/tex]

Therefore, the smallest square number  that can be written using five different  Roman numerals is 10,000.

Next, we divide the number by 24.

[tex]10,000 \div 24 =416 \dfrac{2}{3}[/tex]

The result of the number divided by 24 is [tex]416 \dfrac{2}{3}[/tex]

Answer:

Circumference: 12π + 8 cm,

Area: 48 ( cm )^2

Step-by-step explanation:

This figure is composed of circles, squares, and semicircles. As you can see, the squares indicate that each semicircle should have ( 1 ) the same area, and ( 2 ) the same length ( circumference ). It would be easier to take the circumference of the figure first, as it is composed of arcs part of semicircles the same length.

Circumference of 1 semicircle = [tex]\frac{1}{2}[/tex]( πd ) =  [tex]\frac{1}{2}[/tex]π( 4 ) = 2π ( cm )

Circumference of Figure (composed of 6 semicircles + 2 sides of a square),

We know that 6 semicircles should be 6 [tex]*[/tex] 2π, and as the sides of a square are equal - if one side is 4 cm, the other 3 are 4 cm as well. Therefore the " 2 sides of a square " should be 2

Circumference of Figure = 6 [tex]*[/tex] 2π + 2 = 12π + 8 ( cm )

_____________

The area of this figure is our next target. As you can see, it is composed of 3 semicircles, and the area of 3 semicircles subtracted from the area of 3 squares. Therefore, let us calculate the area of 1 semicircle, and the area of 1 square first.

Area of 1 semicircle = 1/2π[tex]r^2[/tex] = 1/2π[tex](2)^2[/tex] = 2π ( cm ),

Area of 1 square = ( 4 cm )( 4 cm ) = 16 ( [tex]cm^2[/tex] )

So, the area of the figure should be the following -

Area of Figure = 3 [tex]*[/tex] 2π + 3( 16 - 2π ) = 48 ( cm )^2

Answer:

Profit =  $6,922.1

Step-by-step explanation:

Total weight of pecans = 950 kg

1 kg = 1000g

Total weight of pecans in gram = 950 *1000 g = 950,000 g

Note : we have calculated weight in gram as later in question weight of pecans in bag is given in gram so to make uniformity in unit of weight)

Given quantity one bag can store = 250 g

let there be x bag to store 950,000 g of pecan

weight of x bag = quantity one bag can store*x  = 250x (this will be equal to total weight of pecan as given)

250 x= 950,000 g

=> x = 950000/250 = 950*4 = 3800

Thus, there are 3800 bags.

Selling price for 1 bag = $1.90

Selling price for  3800 bag = $1.90*3800 = $7,220

we know profit = selling price - cost price

given cost price of 950 kg pecan = $297.90

Profit = $7,220 - $297.90 = $6,922.1 (answer)

Answer:

4 11/12

Step-by-step explanation:

Well 9 - 4 1/12 is 4 11/12

Answer:

B. 0.07

Step-by-step explanation:

This is a hypothesis test for a proportion.

The claim is that the proportion of convicted drug pushers is significnalty higher than 20%.

Then, the null and alternative hypothesis are:

[tex]H_0: \pi=0.2\\\\H_a:\pi>0.2[/tex]

The sample has a size n=144.

The sample proportion is p=0.25.

[tex]p=X/n=36/144=0.25[/tex]

The standard error of the proportion is:

[tex]\sigma_p=\sqrt{\dfrac{\pi(1-\pi)}{n}}=\sqrt{\dfrac{0.2*0.8}{144}}\\\\\\ \sigma_p=\sqrt{0.001111}=0.0333[/tex]

Then, we can calculate the z-statistic as:

[tex]z=\dfrac{p-\pi}=\dfrac{0.25-0.2}{0.0333}=\dfrac{0.05}{0.0333}=1.5[/tex]

This test is a right-tailed test, so the P-value for this test is calculated as:

[tex]\text{P-value}=P(z>1.5)=0.066\approx0.07[/tex]

Answer:

$34,000

Step-by-step explanation:

Since a one hundred dollar bill is equal to 100, we simply multiply 340 and 100 together:

340(100) = 34000

Answer:

42.5

Step-by-step explanation:

see attached image.

Answer:

42.5

Step-by-step explanation:

So first we have to split this shape into many parts

The simplest way we can do that is by simply drawing a line between the small square and the big rectangle.

Now we calculate the area of each part.

1. Big rectangle

--> So we would just simply multiply the length and width for this one which is 3.5 by 9 --> 3.5 x 9 = 31.5

2. (Left) Right Triangle

Since it's a right triangle we can simply multiply it's L and W then divide by 2

--> 2 x 2 = 4 --> 4/2 = 2

3. (Right) Right Triangle

Same way as previous right triangle l x w / 2

--> 2 x 5 = 10 --> 10/2 = 5

4. Square (Bottom)

And lastly, we have the small square at the bottom

--> l x w = area.

-->given 9 = 2 + x + 5,

x = 9 - 7 --> x = 2

so, 2 x 2 = area --> . 4

Calculate the actual area. of the whole entire shape -->

So this is very simple we just add the area of the shapes (area) we calculated below.

--> 31.5 + 2 + 5 + 4

--> Add parenthasees 31.5 + (2 + 5 + 4)

[To make calculating simpler]

=> 11 + 31.5

=> 32.5 + 10

=> 42.5

Hope this helps!

Answer:

-5

Step-by-step explanation:

its what you multiply by to get the next number

Answer:

Option D is the correct option.

Step-by-step explanation:

Diameter (d) = 10 yd

Radius(r) = 10/2 = 5 yd

Slant height (l)= 12.1 yd

We know,

Lateral surface area of cone:

[tex]\pi \: r \: l[/tex]

[tex] = 3.14 \times 5 \times 12.1[/tex]

[tex] = 189.97 \: {yd}^{2} [/tex]

which is nearly 190.07 square yards.

Hope this helps...

Good luck on your assignment..

Answer:

[tex]190.07 {yd}^{2} [/tex]

Step-by-step explanation:

[tex]lateral \: \: area \\ = \pi \: rl \\ = 3.14 \times 5 \times 12.1 \\ = 189.97[/tex]

189.97 square yards which is nearly 190.07 square yards

Answer:

Summation of the non variable Expression within the quality sign

1/2 + 1-2x= -13/2

3/2-2x= -13/2

Step-by-step explanation:

1/2-1/3(6x-3)=-13/2

First step

Using the distributive property to simply

1/2-(6x/3)+(3/3)=-13/2

1/2 -2x +1 = -13/2

Second step

Summation of the non variable Expression within the quality sign

1/2 + 1-2x= -13/2

3/2-2x= -13/2

Third step

Isolating the variable Expression by using the addition property of equality

-2x = -13/2 - 3/2

-2x = -16/2

Fourth step

Isolating the variable by using the division property of equality

-2x = -16/2

X = -16/2 * -1/2

X = -16/-4

X= 4

Answer:

Simplify by combining like terms

Step-by-step explanation:

Answer: Rent = 29%,  Food = 21%,    Fun = 17%

Step-by-step explanation:

Rent =     $433

Food =    $320

Fun =       $260

Other =   $487  

TOTAL = $1500

[tex]\dfrac{Rent}{Total}=\dfrac{433}{1500}\quad =0.2886\quad =\large\boxed{29\%}\\\\\\\dfrac{Food}{Total}=\dfrac{320}{1500}\quad =0.2133\quad =\large\boxed{21\%}\\\\\\\dfrac{Fun}{Total}=\dfrac{260}{1500}\quad =0.1733\quad =\large\boxed{17\%}[/tex]

Answer:

Sum of Interior Angles = (Number of Sides -2) • 180 degrees

Sum of Interior Angles = (8 -2) * 180 = 1,080

Answer:

Step-by-step explanation:

greatest number=8643

smallest number=3468

difference=8643-3468=5175

6.1.  DCCLVI

CDXCIV

(II) 74,746

Answer:

The 90% confidence interval for the mean time that the drug will take to reduce all fevers for all people is between 304 minutes and 336 minutes

Step-by-step explanation:

We have the standard deviation for the sample, so we use the t-distribution to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 40 - 1 = 39

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 39 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 1.685

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 1.685\frac{60}{\sqrt{40}} = 16[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 320 - 16 = 304 minutes

The upper end of the interval is the sample mean added to M. So it is 320 + 16 = 336 minutes

The 90% confidence interval for the mean time that the drug will take to reduce all fevers for all people is between 304 minutes and 336 minutes

Answer :

option C is the correct answer

━━━━━━━☆☆━━━━━━━

▹ Answer

[tex]\frac{13}{4}[/tex]

▹ Step-by-Step Explanation

4 Squares = x/4

13 parts are shaded in so...

The answer would be 13/4.

Hope this helps!

- CloutAnswers ❁

Brainliest is greatly appreciated!

━━━━━━━☆☆━━━━━━━

Answer:

52°i think

Step-by-step explanation:

148°-96°=52°

Answer:

The answer is below

Step-by-step explanation:

The answer is 52 degrees

The third option in the line

Hope the answer helps

Answer:

27m

Step-by-step explanation:

It's the Pythagorean Theorem.

20^2+18^2=c^2

400+324=c^2

724=c^2

take the square root of both sides

26.9m=c

to the nearest meter = 27

Answer: 36 children

Step-by-step explanation:

3/4 of the class plays basketball.  Thus 3/4x=27.  Multiply each side by 4/3 to get x = 36

Answer:

15 days

Step-by-step explanation:

The pool is 5 ft deep.

5 ft * 12 in/ft = 60 in

The pool is 60 inches deep.

60 in/4 in = 15

Answer: 15 days

Step-by-step explanation:

You just have to plug the numbers they give you into the equation. For the first one, you have 0 + 5y = 10; 5y = 10; y = 2. For the second one, x + 5(0) = 10; x + 0 = 10; x = 10. And lastly, for the third one, x + 5(6) = 10; x + 30 = 10; x = -20.