I litterally don't understand how to do this- ​

Answer:

[11.906 ; 12.894]

Step-by-step explanation:

Given :

Sample mean, xbar = 12.4

Sample standard deviation, s = 1.7

Sample size, n = 48

We use the T distribution since we are using the sample standard deviation;

α - level = 95% ; df = n - 1 = 48 - 1 = 47

Tcritical = T(1 - α/2), 47 = 2.012

Using the confidence interval for one sample mean

Xbar ± Tcritical * s/√n

12.4 ± (2.012 * 1.7/√48)

12.4 ± 0.4936922

C. I = [11.906 ; 12.894]

Answer:

[tex]216\ km^2[/tex]

Step-by-step explanation:

1. Approach

The surface area of a three-dimensional figure is the two-dimensional distance around the figure.  The easiest way to find the surface area of a figure is to find the area of each of its facets, then add up the area to get the total surface area. The given pyramid is composed of four congruent triangles and a square. Find the area of one of the triangles, and then the area of the rectangle. Multiply the area of the triangle by four to account for the fact that there are four congruent triangles. Then add the area of the base to the result, the result attained is the surface area of the prism.

2. Find the area of the triangles

The formula to find the area of a triangle is the following:

[tex]A_t=\frac{b*h}{2}[/tex]

Where (b) represents the base and (h) represents the height of the triangle. Substitute the given values into the formula and solve for the answer.

[tex]A_t=\frac{b*h}{2}[/tex]

[tex]A_t=\frac{9*7.5}{2}[/tex]

[tex]A_t=\frac{67.5}{2}[/tex]

[tex]A_t=33.75[/tex]

3. Find the area of the rectangle

The formula to find the area of a rectangle is the following,

[tex]A_r=b*h[/tex]

Substitute the given values in and solve,

[tex]A_r=b*h[/tex]

[tex]A_r=9*9[/tex]

[tex]A_r=81[/tex]

4. Find the total surface area

Multiply the area of the triangle by four to account for the fact that there are four triangles. Then add its area to the area of the rectangle.

[tex]A_t+A_t+A_t+A_t+A_r=A[/tex]

[tex]4(A_t)+(A_r)=A[/tex]

[tex]4*33.75+81=A[/tex]

[tex]135+81=A[/tex]

[tex]216=A[/tex]

Answer:

$7800

Step-by-step explanation:

1. Principal x interest x rate

So: $7500 + 4% (0.04) x 1 year = $300

2. Interest + Principal

So: $7500 + $300

Mrs Lee had $7800 in the bank.

We usually write explicit functions as one variable in terms of another variable. A simple example of an explicit function is a linear function, such as y = 4x - 7. This function is written as the dependent variable y in terms of the independent variable x.

Answer:

$304

Step-by-step explanation:

4 Windows (each window has 1 blind and 2 panels of curtains)

1 blind = $20 * 4 = $80

1  panels curtains = $28 * 2 = $56 * 4 = $224

$80 + $224 = $304

Answer:

9

Step-by-step explanation:

90+81+mising angle=180, missing angle is 9

Answer:

(11.242 ; 12.958)

Step-by-step explanation:

The confidence interval is obtained using the relation :

C. I = xbar ± Zcritical * s/√n

Given that ::

xbar = 12.1 ;

Standard deviation, s = 16.6

n = 1012

C. I = 12.1 ± 1.645 * (16.6/√1012)

C.I = 12.1 ± 0.8583881

C. I = 11.242 ; 12.958

9514 1404 393

Answer:

Step-by-step explanation:

1a. Vertical angles share a vertex and are composed of opposite rays. Here, angles 2 and 4 are vertical angles.

1b. Consecutively numbered angles are adjacent, as are angles 1 and 5. The pairs of interest can be chosen from ...

  1&2, 2&3, 3&4, 4&5, 5&1

__

2. Angles 1 and 3 have the same measure, because they are vertical angles. Then we have ...

  78° = (5x -2)°

  80 = 5x . . . . . . . divide by °, add 2

  16 = x . . . . . . . divide by 5

Answer:

"Members of a population are organized in clusters, each of which is representative of the population, and then whole clusters are randomly selected to make up the sample"

Step-by-step explanation:

In cluster random sampling, "the population is divided, usually geographically, into groups that generally have the same size.  A certain number of groups are randomly chosen, and every individual in the chosen groups are chosen for the sample."

In accord with this logic, the second choice, "Members of a population are organized in clusters, each of which is representative of the population, and then whole clusters are randomly selected to make up the sample" seems to be correct.

NOTE: This may not be the correct answer. I am simply basing my answer on the definition I have learnt.

Answer:

B

Step-by-step explanation:

Answer:

2*3+5=11

Step-by-step explanation:

Answer:

[tex]\boxed {\boxed {\sf 11}}[/tex]

Step-by-step explanation:

We are given the following function and asked to find the output if the input is 3.

[tex]f(x)= 2x+5[/tex]

The input is what is plugged into the function and its variable is x. The output is the result of plugging in the input and its variable is y.

Substitute 3 in for x,

[tex]f(3)= 2(3)+5[/tex]

Solve according to PEMDAS: Parentheses, Exponents, Multiplication, Division, Addition, Subtraction. Multiply 2 and 3.

[tex]f(3)= 6+5[/tex]

Add.

[tex]f(3)= 11[/tex]

If the input is 3, then the output is 11.

Answer:

8000 and 12000 respectively

Step-by-step explanation:

Let the amount invested in first account be x and y be the amount invested in the second account.

ATQ, x+y=20000 and 1280=(7/100)*x+(6/100)*y

x=8000 and y=12000.

Answer:

17.5ml- of 10 percent solution, 17.5ml- of 20 percent solution

Step-by-step explanation:

35:100*15=5.25- ml of alkali in the base solution

Suppose we need x ml of 10 percents solution and 35-x - of 20 percents.

Then The quantity of alkali in the first one (10 percents) is x/100*10=0.1x

when in the second one we have (35-x)/100*20= 7-0.2x of alkali

0.1x+7-0.2x=5.25

7-0.1x= 5.25

0.1x=1.75

x=17.5- 0f 10 percents

35-17.5=17.5 - of 20 percents

Step-by-step explanation:

132 = 100×1+3×10+2×1

480 = 100×4+8×10+0×1

302 = 100×3+0×10+2×1

1/10 to get your answer

10÷100=

0.1=1/10

Answer:

Yes. the Psychologist can confirm his theory that the attitudes have changed over time, based on the first and second surveys.

The expected value for the number of respondents who are optimistic is:

= 16.25

Step-by-step explanation:

Attitude                   1st Survey      2nd Survey

Optimistic                     7%                    6%

Slightly Optimistic       9%                     6%

Slightly Pessimistic    31%                   37%

Pessimistic                53%                   51%

Expected value of optimistic respondents:

Attitude                    

Optimistic      Expected Value

1st Survey        8.75 (250 * 7% * 50%)  

2nd Survey      7.50 (250 * 6% * 50%)

Total EV         16.25

Answer:

C

Step-by-step explanation:

It is 8.6 because we are finding the difference and using subtraction.  

So I did 68.8-59.9 and I got 8.6

Answer:

the correct answer is |x – 18| ≤ 4

just took the test

Step-by-step explanation:

Set up a ratio:

6/11 = x/26

Cross multiply:

11x = 156

Divide both sides by 11:

X = 14.18 feet ( round answer as needed.)

Answer:

Step by step proof shown below.

Step-by-step explanation:

To prove the equation, you need to apply the Logarithm quotient rule and the Logarithm power rule. Here's how the quotient rule looks like.

[tex]log_b(x/y) = log_b(x) - log_b(y)[/tex]

And here's how the power rule looks like

[tex]log_a(x)^n = nlog_a(x)[/tex]

First let's apply the quotient rule.

[tex]\frac{f(x+h)-f(x)}{h} = \frac{log_a(x+h)-log_a(x) }{h} = \frac{log_a(\frac{x+h}{x} )}{h}[/tex]

Now we can do some quick simplification, and apply the power rule.

[tex]\frac{1}{h} log_a(1 + \frac{h}{x} ) = log_a(1+\frac{h}{x} )^\frac{1}{h}[/tex]

Answer:

1.84

Step-by-step explanation:

If you like my answer than please mark me brainliest thanks

Answer:

Where is the rest?

Step-by-step explanation:

%7"7:7;9

9514 1404 393

Answer:

   0.0056

Step-by-step explanation:

  f(x) = √(49 +x)

  f'(x) = 1/(2√(49 +x))

A linear approximation of f(x) expanded about x=0 is ...

  f(x) ≈ f(0) + f'(0)x = 7 +x/(2·7)

Then for √53, we have x=4

  f(4) ≈ 7 +4/14 = 7 2/7 . . . . . approximate √53 using differentials

__

The calculator value of √53 is about 7.280110, so the difference in results is ...

  approx - actual ≈ 7.285714 -7.280110 = 0.005604 ≈ 0.0056

[tex] \frac{ {x}^{2} }{4} - \frac{ {y}^{2} }{21} = 1[/tex]

[tex] \frac{(x - h)^{2} }{ {a}^{2} } - \frac{(y - k) ^{2} }{ {b}^{2} } = 1 \\ [/tex]

[tex]distance = \sqrt{(x2 - x1) ^{2} + (y2 - y1) ^{2} } \\ c = \sqrt{(( - 5) - 0)^{2} + (0 - 0) ^{2} } \\ c = \sqrt{ {5}^{2} } \\ c = 5[/tex]

[tex]b = + \sqrt{21} , - \sqrt{21} [/tex]

[tex]m = \frac{y2 - y1}{x2 - x1} = \frac{0 - 0}{0 - ( -5 )} = 0[/tex]

[tex] \frac{(x - h)^{2} }{ {a}^{2} } - \frac{(y - k) ^{2} }{ {b}^{2} } = 1 \\ [/tex]

[tex]\frac{(x - 0)^{2} }{ {2}^{2} } - \frac{(y - 0) ^{2} }{ { \sqrt{2} }^{2} } = 1 \\ [/tex]

[tex] \frac{ {x}^{2} }{4} - \frac{ {y}^{2} }{21} = 1[/tex]

I hope I helped you^_^

Answer:

124,503 round to 125,000

Step-by-step explanation:

4 is in the thousands place

We look at the hundreds place

5 is in the hundreds place.  Since 5 is 5 or greater, we round the 4 up

124,503 round to 125,000

Answer:

0.375 dollars

Step-by-step explanation:

1 pound = 16 oz

1 oz = 1/16 pound

2 oz = 2/16

2/16 * 3 = 0.375

9514 1404 393

Answer:

  0.06164

Step-by-step explanation:

The effective annual rate obtained by compounding nominal annual rate r monthly is ...

  eff rate = (1 +r/12)^12 -1

Then the value of r is ...

  r = 12×((eff rate) +1)^(1/12) -1)

For the given effective rate, that is ...

  r = 12×(1.06341^(1/12) -1) ≈ 0.06164 . . . . nominal annual interest rate

The partial fraction expansion takes the form

-6x/((x + 2) (x + 8)) = a/(x + 2) + b/(x + 8)

Both factors in the denominator are linear, so the numerators in the corresponding partial fractions have degree 1 - 1 = 0 and are thus constants.

Combine the fractions on the right side into one with a common denominator, then set the numerators on both sides of the equation equal to each other:

-6x = a (x + 8) + b (x + 2)

Expand the right side and collect terms by powers of x :

-6x = (a + b) x + (8a + 2b)

It follows that

a + b = -6   and   8a + 2b = 0

==>   a = -2   and   b = 8

So we end up with

-6x/((x + 2) (x + 8)) = -2/(x + 2) + 8/(x + 8)

A fraction means division.

To find the decimal equivalent of a fraction, divide the top number by the bottom number.