Students in a statistics class are conducting a survey to estimate the mean number of units students at their college are enrolled in. The students collect a random sample of 48 students. The mean of the sample is 12.4 units. The sample has a standard deviation of 1.7 units.

Required:
What is the 95% confidence interval for the average number of units that students in their college are enrolled in?

Answer:

Result is statistically significant.

Step-by-step explanation:

Given that :

Chisquare statistic, χ² = 67.81

Critical value for the distribution, χ²critical = 3.84

α = 0.05

The Decison region :

If χ² statistic > Critical value ; Reject H0 ; this. Eans that result is statistically significant.

Therefore, since, 67.81 > 3.84 ; This means that the result is statistically significant at 0.05

Answer:

3.4

Step-by-step explanation:

The angle bisector theorem states that for a triangle that is bisected, the ratio between the two edges in each of the triangles that form are proportional to each other.

For this triangle, the bisector splits the triangle into ΔABD and ΔACD. The edges of ΔABD are BD and AB, while the edges of ΔACD are CD and AC. Therefore, we can say that BD/AB = CD/AC . Note that both parts of line that is bisected (BC) are on top, while the other edge sides are on the bottom. *

BD/AB = CD/AC

2.6/4.9 = ? / 6.5

multiply both sides by 6.5 to isolate the ?

2.6 * 6.5 / 4.9 = ? ≈ 3.4

* this can also be rearranged so that AB/BD = AC/CD, but it is vital to ensure that either both sides that are part of the larger triangle are on top or both parts of the bisected line are on top

Step-by-step explanation:

the graph will be compressed vertically

Answer:

c. [0.25 0.75] ^T

Step-by-step explanation:

Bernoulli distribution is used to identify number of successes and failures in the selected sample. In the given problem Ber distribution trial is 0.25. There will be categorical distribution of 0.75 and the trial will be done on parameter vector.

Answer:

base-2 base-10

110011 = 51

110100 = 52

110101 = 53

110110 = 54

21 more rows

Answer:

y=2x+1

Step-by-step explanation:

y is directly proportional to x if it increases as x increases

Answer:

Yes 7i is the answer

Step-by-step explanation:

they are equivalent.

Answer:

Step-by-step explanation:

Functions are always relations, but not every relation is a function. This passes the vertical line test so it is a function. Since it's not a line, it's not linear. B is your choice.

Answer:

7.6

Step-by-step explanation:

Mean = (sum of numbers)/amount of numbers

11 + 4 + 6 + 7 + 5 +10 +9 + 21 + 3 + 0 = 76

76/10 = 7.6

9514 1404 393

Answer:

  (-1, -3)

Step-by-step explanation:

Each coordinate is multiplied by the dilation factor when dilation is centered at the origin.

  (1/4)(-4, -12) = (-1, -3) . . . . the image of the given point

Answer:

yes

Step-by-step explanation:

The complete sentence is,

A kite is a convex quadrilateral.

We have to given that,

To find a kite is which type of a quadrilateral.

We know that,

A quadrilateral known as a kite has four sides that may be divided into two pairs of neighboring, equal-length sides.

The two sets of equal-length sides of a parallelogram, however, are opposite one another as opposed to being contiguous.

Hence, The complete sentence is,

A kite is a convex quadrilateral.

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Answer:

18 dollars

Step-by-step explanation:

sunglasses = 6 dollars

sandals = 3 * sunglasses

             = 3 * 6 dollars

             = 18 dollars

Answer:

The correct answer is B. It will take them 7.2 hours.

Step-by-step explanation:

Given that to collect data on the signal strengths in a neighborhood, Briana must drive from house to house and take readings, and she has a graduate student, Henry, to assist her, and Briana figures it would take her 12 hours to complete the task working alone, and that it would take Henry 18 hours if he completed the task by himself, to determine how long will it take Briana and Henry to complete the task together the following calculation must be performed:

1/12 + 1/18 = X

18 / (12 x 18) + 12 / (18 x 12) = X

30/216 = X

5/36 = X

36/5 = 7.2

Therefore, they will be able to finish the task in 7.2 hours.

Answer:

The answer is "2.4049"

Step-by-step explanation:

Calculating the test of Hypothesis: [tex]H_{0}: 23\% \ \text{off all adults which reconize the compony's logo}\\\\H_{1}: \text{more than 23\% of adult recornise the compony's logo}\\\\[/tex]

that is

[tex]H_{0}: p=0.23\ against \ H_{1}:p>0.01\\\\Z=\frac{P-p}{\sqrt{\frac{p(1-p)}{n}}}\sim N(0,1)\\\\[/tex]

Given:

[tex]p= 0.23\\\\ \therefore \\\\1-p=0.77\\\\n=1200\\\\ P=\frac{311}{1200}=0.2591\\\\\therefore\\\\Z= \frac{0.2591-0.23}{\sqrt{((0.23)\times \frac{(1-0.23))}{1200}}}=2.4049[/tex]

Z=2.576 tabled value. Because Z is 2.4049, that's less than Z stated, there is no indication that a null hypothesis is rejectable, which means that 23% of all adults record the logo of the Company.

Answer:

-3

Step-by-step explanation:

Slope is y2 - y1 / x1 - x2.

So, let's take two random points; I have chosen (0, 3) and (2, -3).

Excellent. Let's calculate the slope.

Slope = (-3 - 3) / (2 - 0) = -6 / 2 = -3.

Hope this helps!

Answer:

3 1/2<5 1/2

Step-by-step explanation:

The first answer is correct

Step-by-step explanation:

Three and one half

[tex] = 3 \frac{1}{2} [/tex]

Less than symbol ( < )

Five and one half

[tex] = 5\frac{1}{2} [/tex]

So, equation will be,

[tex]3 \frac{1}{2} < 5 \frac{1}{2} [/tex]

Hence, your chosen option is correct

Answer:

a) 25/35

b) 30/42

Step-by-step explanation:

a)

Variable x = denominator if numerator is 25

5/7 = 25/x

5 × x = 7 × 25

5x = 175

x = 35

b)

Variable y = numerator if denominator is 42

5/7 = y/42

5 × 42 = 7 × y

210 = 7y

30 = y

25/35

30/42

To get 25/35 multiply by 5

To get 30/42 multiply by 6

Answer:

the ratio of lengths of the two rods, Aluminum to Invar is 11.27

Step-by-step explanation:

coefficient of linear expansion of aluminum, [tex]\alpha _{Al} = 23 \times 10^{-6} /K[/tex]

Coefficient of linear expansion of Invar, [tex]\alpha _{Iv} = 1.2 \times 10^{-6}/K[/tex]

Linear thermal expansion is given as;

[tex]\Delta L = L_0 \times \alpha\times \Delta T\\\\where;\\\\L_0 \ is \ the \ original \ length \ of \ the \ metal\\\\\Delta L \ is \ the \ increase \ in \ length[/tex]

The increase in length of Invar is given as;

[tex]\Delta L_{Iv} = L_0_{Iv} \times \alpha _{Iv}\times \Delta T_{Iv}[/tex]

The increase in length of the Aluminum;

[tex]\Delta L_{ Al} = L_0_{Al} \times \alpha _{Al} \times \Delta T_{Al}\\\\from \ the\ given \ question, \ the \ relationship \ between \ the \ rods \ is \ given \ as\\\\ L_0_{Al} \times \alpha _{Al} \times \frac{1}{3} \Delta T_{Iv}= 2( L_0_{Iv} \times \alpha _{Iv} \times \Delta T_{Iv})\\\\ L_0_{Al} \times \alpha _{Al} \times \Delta T_{Iv}= 6( L_0_{Iv} \times \alpha _{Iv} \times \Delta T_{Iv})\\\\ L_0_{Al} \times \alpha _{Al} \times \Delta T_{Iv} = 6L_0_{Iv} \times 6\alpha _{Iv} \times 6 \Delta T_{Iv}\\\\[/tex]

[tex]\frac{L_0_{Al}}{6L_0_{Iv} } = \frac{6\alpha _{Iv} \ \times \ 6 \Delta T_{Iv}}{\alpha _{Al} \ \times \ \Delta T_{Iv}} \\\\\frac{L_0_{Al}}{6L_0_{Iv} } = \frac{6\alpha _{Iv} \ \times \ 6}{\alpha _{Al} \ } \\\\\frac{L_0_{Al}}{L_0_{Iv} } = 6^3(\frac{\alpha _{Iv} }{\alpha _{Al} } )\\\\\frac{L_0_{Al}}{L_0_{Iv} } = 6^3(\frac{1.2 \times 10^{-6} }{23\times 10^{-6} } )\\\\\frac{L_0_{Al}}{L_0_{Iv} } = 6^3(\frac{1.2}{23} )\\\\\frac{L_0_{Al}}{L_0_{Iv} } = \frac{259.2}{23} \\\\\frac{L_0_{Al}}{L_0_{Iv} } = 11.27[/tex]

Therefore, the ratio of lengths of the two rods, Aluminum to Invar is 11.27

The ratio of the lengths of the two rods which is length of aluminum to length of Invar rod is; 11.27

Formula for linear thermal expansion is;

ΔL = L × α × ΔT

Where;

ΔL is change in original length

L is original length

α is coefficient of linear expansion

ΔT is change in temperature

We are told that increase in length of aluminum rod is twice the increase in length of an Invar rod with only a third of the temperature increase.

Thus;

ΔL = 2ΔL

ΔT for the aluminum rod = ⅓ΔT for the Invar rod.

Thus, we have;

L_al × α_al × ⅓ΔT = 2L_in × 2α_in × 2ΔT

ΔT will cancel out to give;

⅓(L_al × α_al) = 2L_in × 2α_in × 2

Multiply both sides by 3 to get;

(L_al × α_al) = 6L_in × 6α_in × 6

From online tables, the linear coefficient of expansion of aluminum is 23 × 10^(-6) C¯¹

While the coefficient of thermal expansion for Invar rod is 1.2 × 10^(-6) K¯¹

Thus;

L_al × 23 × 10^(-6) = 6L_in × (6 × 1.2 × 10^(-6)) × 6

L_al/L_in = (6 × 6 × 1.2 × 10^(-6) × 6)/(23 × 10^(-6))

L_al/L_in = 11.27

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Answer: 996 ft2

Step-by-step explanation:

Add up the area of all 6 sides of the prism:

(10 · 13) + (10 · 13) + (10 · 16) + (10 · 16) + (16 · 13) + (16 · 13)

= 130 + 130 + 160 + 160 + 208 + 208

=996 ft²

Answer:

B) 996 ft2

Step-by-step explanation:

Solution :

Given data :

20.1     33.5     21.7      58.4     23.2     110.8     30.9

24.0    74.8     60.0

n = 10

Range : Arranging from lowest to highest.

20.1,   21.7,   23.2,    24.0,   30.9,    33.5,    58.4,    60.0,    74.8,   110.8

Range = low highest value - lowest value

           = 110.8 - 20.1

           = 90.7

Mean = [tex]$\frac{\sum x}{n}$[/tex]

         [tex]$=\frac{20.1+21.7+23.2+24.0+30.9+33.5+58.4+60.0+74.8+110.8}{10}$[/tex]

          [tex]$=\frac{457.4}{10}$[/tex]

         [tex]$=45.74$[/tex]

Sample standard deviation :

[tex]$S=\sqrt{\frac{1}{n-1}\sum(x-\mu)^2}$[/tex]

[tex]$S=\sqrt{\frac{1}{10-1}(20.1-45.74)^2+(21.7-45.74)^2+(23.2-45.74)^2+(24.0-45.74)^2+(30.9-45)^2}$[/tex]  

      [tex]\sqrt{(33.5-45.74)^2+(58.4-45.74)^2+(60.0-45.74)^2+(74.8-45.74)^2+(110.8-45.74)^2}[/tex]

[tex]$S=\sqrt{\frac{1}{9}(657.4+577.9+508.0+472.6+220.2+149.8+160.2+203.3+844.4+4232.8)}$[/tex][tex]$S=\sqrt{\frac{1}{9}(8026.96)}$[/tex]

[tex]$S=\sqrt{891.88}$[/tex]

S = 29.8644

Variance = [tex]S^2[/tex]

               [tex]=(29.8644)^2[/tex]

               = 891.8823

Answer:

(m-6+2root3)(m-6-2root3)

Step-by-step explanation:

m^2 - 12m +36 -12

= (m-6)^2 - 12

= (m-6+2root3)(m-6-2root3)[root 12 = 2root3]

Answer

4.8 degrees to the nearest tenth.

Step-by-step explanation:

The slope = rise / run = opposite side / adjacent side.

So the angle of inclination is the angle whose tangent is 1/12.

To the nearest tenth of a degree it is 4.8 degrees.

Answer:

see below

Step-by-step explanation:

7.  We can use the law of sines to solve

sin C         sin B

-------- = ----------

AB              AC

sin 45       sin 32

--------- = ----------

AB            6

Using cross products

6 sin 45 = AB sin 32

6 sin 45 / sin 32 = AB

8.00620 = AB

To the nearest tenth

8.0= AB

9.    We can use the law of sines to solve

sin A         sin B

-------- = ----------

CB              AC

sin A       sin 88

-------- = -----------

13             15

Using cross products

15 sin A = 13 sin 88

sin A = 13/15 sin 88

Taking the inverse sin of each side

sin^-1(sin A) = sin ^-1 (13/15 sin88)

A = 60.01298726

To the nearest tenth

A =60.0

============================================

Explanation for part (a)

All distances mentioned are in feet.

We'll have a right triangle which allows us to apply the pythagorean theorem. Refer to the diagram below.

a^2+b^2 = c^2

x^2+y^2 = z^2

Apply the derivative to both sides with respect to t. We'll use implicit differentiation and the chain rule.

[tex]x^2+y^2 = z^2\\\\\frac{d}{dt}[x^2+y^2] = \frac{d}{dt}[z^2]\\\\\frac{d}{dt}[x^2]+\frac{d}{dt}[y^2] = \frac{d}{dt}[z^2]\\\\2x*\frac{dx}{dt}+2y*\frac{dy}{dt}=2z*\frac{dz}{dt}\\\\x*\frac{dx}{dt}+y*\frac{dy}{dt}=z*\frac{dz}{dt}\\\\[/tex]

Now we'll plug in (x,y,z) = (4000,3000,5000). The x and y values are given. The z value is found by use of the pythagorean theorem. Ie, you solve 4000^2+3000^2 = z^2 to get z = 5000. Or you could note that this is a scaled copy of the 3-4-5 right triangle.

We know that dx/dt = 0 because the horizontal distance, the x distance, is not changing. The rocket is only changing in the y direction. Or you could say that the horizontal speed is zero.

The vertical speed is dy/dt = 800 ft/s and it's when y = 3000. It's likely that dy/dt isn't the same value through the rocket's journey; however, all we care about is the instant when y = 3000.

Let's plug all that in and isolate dz/dt

[tex]4000*0+3000*800=5000*\frac{dz}{dt}\\\\2,400,000=5000*\frac{dz}{dt}\\\\\frac{dz}{dt} = \frac{2,400,000}{5000}\\\\\frac{dz}{dt} = 480\\\\[/tex]

At the exact instant that the rocket is 3000 ft in the air, the distance between the camera and the rocket is changing by an instantaneous speed of 480 ft/s.

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

Explanation for part (b)

Again, refer to the diagram below.

We have theta (symbol [tex]\theta[/tex]) as the angle of elevation. As the rocket's height increases, so does the angle theta.

We can tie together the opposite side y with the adjacent side x with the tangent function of this angle.

[tex]\tan(\text{angle}) = \frac{\text{opposite}}{\text{adjacent}}\\\\\tan(\theta) = \frac{y}{x}[/tex]

Like before, we'll apply implicit differentiation. This time we'll use the quotient rule as well.

[tex]\tan(\theta) = \frac{y}{x}\\\\\frac{d}{dt}[\tan(\theta)] = \frac{d}{dt}\left[\frac{y}{x}\right]\\\\\sec^2(\theta)*\frac{d\theta}{dt} = \frac{\frac{dy}{dt}*x - y*\frac{dx}{dt}}{x^2}\\\\\sec^2(\theta)*\frac{d\theta}{dt} = \frac{800*4000 - 3000*0}{4000^2}\\\\\sec^2(\theta)*\frac{d\theta}{dt} = \frac{3,200,000}{16,000,000}\\\\\sec^2(\theta)*\frac{d\theta}{dt} = \frac{32}{160}\\\\\sec^2(\theta)*\frac{d\theta}{dt} = \frac{1}{5}\\\\[/tex]

Let's take a brief detour. We'll return to this later. Recall earlier that [tex]\tan(\theta) = \frac{y}{x}\\\\[/tex]

If we plug in y = 3000 and x = 4000, then we end up with [tex]\tan(\theta) = \frac{3}{4}\\\\[/tex] which becomes [tex]\tan^2(\theta) = \frac{9}{16}[/tex]

Apply this trig identity

[tex]\sec^2(\theta) = 1 + \tan^2(\theta)[/tex]

and you should end up with [tex]\sec^2(\theta) = 1+\frac{9}{16} = \frac{25}{16}[/tex]

So we can now return to the equation we want to solve

[tex]\sec^2(\theta)*\frac{d\theta}{dt} = \frac{1}{5}\\\\\frac{25}{16}*\frac{d\theta}{dt} = \frac{1}{5}\\\\\frac{d\theta}{dt} = \frac{1}{5}*\frac{16}{25}\\\\\frac{d\theta}{dt} = \frac{16}{125}\\\\\frac{d\theta}{dt} = 0.128\\\\[/tex]

This means that at the instant the rocket is 3000 ft in the air, the angle of elevation theta is increasing by 0.128 radians per second.

This is approximately 7.334 degrees per second.

The distance from the television camera to the rocket is changing at 480 ft/s while the camera's angle of elevation is changing at 0.128 rad/s

Let x represent the distance from the camera to the rocket and let h represent the height of the rocket.

a)

[tex]x^2=h^2+4000^2\\\\2x\frac{dx}{dt}=2h\frac{dh}{dt} \\\\x\frac{dx}{dt}=h\frac{dh}{dt} \\\\At \ h=3000\ ft, \frac{dh}{dt}=800\ ft/s;\\x^2=3000^{2} +4000^2\\x=5000\\\\\\x\frac{dx}{dt}=h\frac{dh}{dt} \\\\5000\frac{dx}{dt}=3000*800\\\\\frac{dx}{dt}=480\ ft/s[/tex]

b)

[tex]tan(\theta)=\frac{h}{4000} \\\\h=4000tan(\theta)\\\\\frac{dh}{dt}=4000sec^2(\theta)\frac{d\theta}{dt} \\\\\\At\ h=3000\ ft;\\\\tan\theta = \frac{3000}{4000}=\frac{3}{4} \\\\sec^2(\theta)=1+tan^2(\theta)=1+(\frac{3}{4})^2=\frac{25}{16} \\\\\\\frac{dh}{dt}=4000sec^2(\theta)\frac{d\theta}{dt}\\\\800=4000*\frac{25}{16}* \frac{d\theta}{dt}\\\\\frac{d\theta}{dt}=0.128\ rad/s[/tex]

Hence, The distance from the television camera to the rocket is changing at 480 ft/s while the camera's angle of elevation is changing at 0.128 rad/s

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Answer:

The probability tree is;

                            0.95        [tex](+)[/tex]

                   [tex](S)[/tex]

          0.1              0.05        [tex](-)[/tex]

[  P  ]

          0.9             0.15          [tex](+)[/tex]                                                        

                  [tex](S_{no})[/tex]    

                             0.85         [tex](-)[/tex]        

Step-by-step explanation:

Given the data in the question;

10% of the rugby team members use steroids

so Probability of using steroid; P( use steroid ) = 10% = 0.10

Probability of not using steroid; P( no steroid use ) = 1 - 0.10 = 0.90

Since the test show positive for an athlete who uses steroids, 95% of the time.

Probability of using steroids and testing positive = 95% = 0.95

Probability of using steroids and testing Negative = 1 - 0.95 = 0.05

Also from the test, 15% of all steroid-free individuals also test positive.

so

Probability of not using steroids and testing positive = 15% = 0.15

Probability of not using steroids and testing negative = 1 - 0.15 = 0.85

To set up the probability tree, Let;

[tex](S)[/tex] represent steroid use

[tex](S_{no})[/tex] represent no steroid use

[tex](+)[/tex] represent test positive

[tex](-)[/tex] represent test negative

so we have;

                            0.95        [tex](+)[/tex]

                   [tex](S)[/tex]

          0.1              0.05        [tex](-)[/tex]

[  P  ]

          0.9             0.15          [tex](+)[/tex]                                                        

                  [tex](S_{no})[/tex]    

                             0.85         [tex](-)[/tex]        

9514 1404 393

Answer:

Step-by-step explanation:

If n represents the number, we have ...

  10(-270 +n) = -20 . . . an equation for n

__

The solution can be found as ...

  -270 +n = -2 . . . . . divide by 10

  n = 268 . . . . . . . add 270

The number is 268.

9514 1404 393

Answer:

  A

Step-by-step explanation:

The parallelogram has rotational symmetry of degree 2. It looks the same after rotation by 180°.

_____

Additional comment

When a figure only looks like itself after a full rotation of 360°, it is said to have rotational symmetry of degree 1. All of the figures here will return to their original appearance after one 360° rotation. So, we assume the intent of the question is to identify figures with a rotational symmetry of degree greater than 1.

Answer:

5<x<29

Step-by-step explanation:

One theorem tells us that if a triangle has two congruent sides and one of the included angle is bigger than the other, the triangle with the included angle that is bigger. has a bigger side than the other.

This is the opposite in this case. The triangles share two sides and we know that the triangle with the side length 18 has a bigger angle than the triangle with the side length 15. So this means that

[tex]48 > 2x - 10[/tex]

Let find the range of x values.

An angle cannot be negative or zero so this means that

[tex]2x - 10 > 0[/tex]

Solve for x.

[tex]2x > 10[/tex]

[tex]x > 5[/tex]

The angle cannot be bigger than 48 so

[tex]48 > 2x - 10[/tex]

Solve for x.

[tex]58 > 2x[/tex]

[tex]29 > x[/tex]

So x must be greater than 5 but less than 29.