Weekly wages at a certain factory are
normally distributed with a mean of
$400 and a standard deviation of $50.
Find the probability that a worker
selected at random makes between
$450 and $500.

Answer:

[tex]A.\ 16\sqrt3\ cm^2[/tex] is the correct answer.

Step-by-step explanation:

Given that:

Side of an equilateral triangle = 8 cm

To find:

Area of the triangle will be:

[tex]A.\ 16\sqrt3\ cm^2[/tex]

[tex]B.\ \dfrac{32}{3} cm^2[/tex]

[tex]C.\ 48\ cm^2[/tex]

[tex]D.\ 36\sqrt3\ cm^2[/tex]

Solution:

First of all, let us have a look at the formula for area of an equilateral triangle:

[tex]A =\dfrac{\sqrt3}{4}a^2[/tex]

Where [tex]a[/tex] is the side of equilateral triangle and an equilateral triangle is a closed 3 sided structure in 2 dimensions which has all 3 sides equal to each other.

Here, we are given that side, [tex]a=8\ cm[/tex]

Putting the value in formula:

[tex]A =\dfrac{\sqrt3}{4}\times 8^2\\\Rightarrow A =\dfrac{\sqrt3}{4}\times 64\\\Rightarrow A =\sqrt3\times 16\\OR\\\Rightarrow \bold{A =16\sqrt3\ cm^2}[/tex]

Hence, [tex]A.\ 16\sqrt3\ cm^2[/tex] is the correct answer.

Answer:

x=6

Step-by-step explanation:

2x+4=16

2x+4-4=16-6

2x=12

x=6

Proof:

2x+4=16

2(6)+4=16

12+4=16

16=16

Hope this helps ;) ❤❤❤

Answer:

find out what x is and it is 6 it is 6 because 2 times 6 is 12 and 12 plus 4 is 16

Step-by-step explanation:

Answer:

38.911≤p≤41.089

Step-by-step explanation:

The formula for calculating confidence interval for a population mean us as shown below;

CI = xbar ± Z×S/√N where;

xbar is the sample mean = 40

Z is the z score at 95% confidence interval = 1.96

S is the standard deviation = 5

N is the sample size = 81

Substituting this parameters in the formula we have;

CI = 40±1.96×5/√81

CI = 40±(1.96×5/9)

CI = 40±(1.96×0.556)

CI = 40±1.089

CI = (40-1.089, 40+1.089)

CI = (38.911, 41.089)

The 95% confidence interval for the population mean is 38.911≤p≤41.089

Answer:

38.9 ≤ U ≤ 41.1

Step-by-step explanation:

Mean, m = 40; standard deviation, α = 5; Confidence limit, U = 95% or 0.95

N = 81

The standard error, α(m) = α/√(N) = 5/√81 =5/9

Using table: 0.95 = 0.0379

Z(0.95) = 2 - 0.0379 = 1.9621 or 1.96

Hence, confidence interval = { m - 1.96(α/√N) ≤ U ≤ m +1.96(α/√N)}

But, 1.96(α/√N) = 1.96 X 5/9 = 1.96 X 0.56 = 1.1

(40 - 1.1 ≤ U ≤ 40 + 1.1)

∴ the confidence interval = 38.9 ≤ U ≤ 41.1

Answer:

Step-by-step explanation:

● h(x) = 2-2x

The domain is {-3,-2,1,5}

● h(-3) = 2-2×(-3) = 2+6 = 8

● h(-2) = 2 -2×(-2) = 2+4 = 6

● h(1) = 2-2×1 = 2-2 = 0

● h(5) = 2-2×5 = 2-10 = -8

The range is {-8,0,6,8}

Answer:

I think you should change it to 4x + 3y

Step-by-step explanation:

hope this helps

Answer:

Step-by-step explanation:

Using the given formula, we put n = 5

[tex]h = 8* {(\frac{1}{2}) ^{n-1}[/tex]

h = 8 / 16

h = 1 / 2 inches

Step-by-step explanation:

The inequality shows by line is

i) 1<=x<=6

OR,

x is an positive integer.

Answer:

Diameter of wheel in millimetres is 660.4

Step-by-step explanation:

Diameter of wheel in inches = 26

given

1 inch = 25.4 millimeters

multiplying RHS and LHS by 26

26*1 inch = 26*25.4 millimeters

=>26 inch = 660.4 mm.

Thus, diameter of wheel in millimetres is 660.4

Answer: Vu is 15 years old now.

Step-by-step explanation:

Let present age of WU be x.

Then, the present age of Vu = 3x

Also, After 25 years

Age of Wu = x+25

According to the question:

[tex](x+25)=2(3x)\\\\\Rightarrow\ x+25=6x\\\\\Rightarrow\5x=25\\\\\Rightarrow\ x=5[/tex]

Present age of Vu = 3(5) = 15

Hence, Vu is 15 years old now.

Answer:

j

Step-by-step explanation:j

Answer:

t= 0.4933

t ≥ t ( 0.025 ,8 ) = 2.306

Since the calculated value of t= 0.4933 is less than t ( 0.025 ,8 ) = 2.306 therefore we accept the null hypothesis at 5 % significance level . On the basis of this we conclude that the book had no effect on their scores.

Step-by-step explanation:

We state our null and alternative hypotheses as

H0: ud= 0 Ha: ud≠0

The significance level is set at ∝= 0.05

The test statistic under H0 is

t= d`/ sd/√n

which has t distribution with n-1 degrees of freedom

The critical region is t ≥ t ( 0.025 ,8 ) = 2.306

Computations

Student       Scores before      Scores after    Difference           d²

                        reading book                    ( after minus before)

1                          720                   740             20                       400

2                        860                   860              0                           0

3                        850                   840             -10                       100

4                        880                   920             40                       1600

5                        860                   890             30                        900

6                        710                    720              10                         100

7                       850                    840              -10                       100

8                      1200                  1240             40                        1600

9                      950                    970              20                           40

∑                    6930                  8020           140                         4840

d`= ∑d/n= 140/9= 15.566

sd²= 1/8( 4840- 140²/9) = 1/8 (4840 - 2177.778) = 2662.22/8= 332.775

sd= 18.2422

t= 3/ 18.2422/ √9

t= 0.4933

Since the calculated value of t= 0.4933 is less than t ( 0.025 ,8 ) = 2.306 therefore we accept the null hypothesis at 5 % significance level . On the basis of this we conclude that the book had no effect on their scores.

Answer:

= 18.2 miles per hour

Step-by-step explanation:

Speed = distance / time

            =82 miles / 4.5 hours

             =18.22222222 miles per hour

             Rounding

             = 18.2 miles per hour

Answer:

Given that

Distance = rate × time

82 = r × 4½

r = 18.2 mph

Answer:

Explained below.

Step-by-step explanation:

Enter the data in an Excel sheet.

(a)

Go to Insert → Chart → Scatter.

Select the first type of Scatter chart.

The scatter plot is attached below.

(b)

The scatter plot with the line of best fit is attached below.

The line of best fit is:

[tex]y=-0.8046x+103.56[/tex]

(c)

Compute the value of x for y = 30 as follows:

[tex]y=-0.8046x+103.56[/tex]

[tex]30=-0.8046x+103.56\\\\0.8046x=103.56-30\\\\x=\frac{73.56}{0.8046}\\\\x\approx 91.42[/tex]

Thus, the Advance Mathematics mark of a student who scores 30 out of 100 in English is 91.42.

(d)

The Pearson's Correlation Coefficient is:

[tex]r=\frac{n\cdot \sum XY-\sum X\cdot \sum Y}{\sqrt{[n\cdot \sum X^{2}-(\sum X)^{2}][n\cdot \sum Y^{2}-(\sum Y)^{2}]}}[/tex]

  [tex]=\frac{14\cdot 44010-835\cdot 778}{\sqrt{[14\cdot52775-(825)^{2}][14\cdot 47094-(778)^{2}]}}\\\\= -0.7062\\\\\approx -0.71[/tex]

Thus, the Pearson's Correlation Coefficient is -0.71.

(e)

A correlation coefficient between ± 0.50 and ±1.00 is considered as a strong correlation.

The correlation between Advanced Mathematics and English results is -0.71.

This implies that there is a strong negative correlation.

The correct answer is B. 0.00

Explanation:

In statistics, two events are mutually exclusive if only one event can occur at one time. For example, if you have a deck of cards with Hearts and Spades, every time you choose a card you will have either Hearts or Spades but not both at the same time as there is not any card that combines Hearts and Spades in the same card. This means it is statistically impossible for two mutually exclusive events to occur at the same time, which means the probability is 0.00.

Answer:

Well this is my opinion I would try to compared both them and see if they have something familiar in their arguments. If not I would try to view their different point of view and write your own opinion about it. I would check out another book about the World War 2 because there's infinite of books about it.

Answer:

The probability that the amount of gas in Sarah's car is exactly 7 gallons is 0.067.

Step-by-step explanation:

Let the random variable X represent the amount of gas in Sarah's car.

It is provided that [tex]X\sim Unif(1, 16)[/tex].

The amount of gas in a car is a continuous variable.

So, the random variable X follows a continuous uniform distribution.

Then the probability density function of X is:

[tex]f_{X}(x)=\frac{1}{b-a};\ a<X<b[/tex]

For a continuous probability distribution the probability at an exact point is 0.

So, to compute the probability that the amount of gas in Sarah's car is exactly 7 gallons use continuity correction on both sides:

P (X = 7) = P (7 - 0.5 < X < 7 + 0.5)

              = P (6.5 < X < 7.5)

              [tex]=\int\limits^{7.5}_{6.5} {\frac{1}{16-1}} \, dx \\\\=\frac{1}{15}\times |x|^{7.5}_{6.5}\\\\=\frac{1}{15}\times (7.5-6.5)\\\\=\frac{1}{15}\\\\=0.0666667\\\\\approx 0.067[/tex]

Thus, the probability that the amount of gas in Sarah's car is exactly 7 gallons is 0.067.

Answer:

A, E

Step-by-step explanation:

There should be 2^8-1 proper subsets of A. Its every one besides { }

Answer:

[tex] \begin{cases} (x - 2)^2 + (y - 2)^2 = 25 \\ y = 5 \end{cases} [/tex]

Solutions: x = 6, y = 5   or   x = -2, y = 5

Step-by-step explanation:

Use a graph.

Plot point (-2, 5). That will be a point on a circle with radius 5.

From point (-2, 5), go right 4 and down 3 to point (2, 2). (2, 2) is the center of the circle.

You now need the equation of a circle with center (2, 2) and radius 5.

Use the standard equation of a circle:

[tex] (x - h)^2 + (y - k)^2 = r^2 [/tex]

where (h, k) is the center and 5 is the radius.

The circle has equation:

[tex] (x - 2)^2 + (y - 2)^2 = 25 [/tex]

To have a single solution, you need the equation of the line tangent to the circle at (-2, 5), but since you want more than one solution, you need the equation of a secant to the circle. For example, use the equation of the horizontal line through point (2, 5) which is y = 5.

System:

[tex] \begin{cases} (x - 2)^2 + (y - 2)^2 = 25 \\ y = 5 \end{cases} [/tex]

To solve, let y = 5 in the equation of the circle.

(x - 2)^2 + (5 - 2)^2 = 25

(x - 2)^2 + 9 = 25

(x - 2)^2 = 16

x - 2 = 4  or x - 2 = -4

x = 6 or x = -2

Solutions: x = 6, y = 5   or   x = -2, y = 5

An example of a nonlinear system that has at least two solutions, one of which is (-2,5) are,

⇒ x² + y² = 29

⇒ 3x + 4y = -2

Mathematical expression is defined as the collection of the numbers variables and functions by using operations like addition, subtraction, multiplication, and division.

Now, This system by starting with the equation of a circle centered at the origin with radius sqrt(29), which is,

⇒ x² + y² = 29.

Then, Added a linear equation that intersects the circle at (-2,5) to create a system with two solutions.

The entire solution set for this system is: (-2, 5) and (7/5, -19/10)

Thus, An example of a nonlinear system that has at least two solutions, one of which is (-2,5) are,

⇒ x² + y² = 29

⇒ 3x + 4y = -2

Learn more about the mathematical expression visit:

brainly.com/question/1859113

#SPJ3

Answer:

66

Step-by-step explanation:

when you plug in 9 for k. you do 6(9) which is 54. then add 12 to 54 and thats ur answer, 66.

Answer:

Mean= 242.5 pounds

Median= 236 pounds

Mode= 208 and 278 pounds

Range=117 pounds

Mid-range= 58.5 pounds

B. The results are likely to be representative because a championship team is most likely representative of the entire league.

Step-by-step explanation:

278 303 186 292  276 205 208 236 278 198 208

Arranged in ascending order is

186 198 205 208 208 236 276 278 278 292 303

Mean = (186 +198+ 205+ 208 +208 +236 + 276+ 278 +278+ 292 +303)/11

Mean =2668/11

Mean= 242.5 pounds

Median = the middle number

Median= 236 pounds

Mode = highest occuring number(s)

Mode= 208 and 278 pounds

Range= highest number- smallest number

Range=303-186

Range=117 pounds

Mid-range= range/2

Mid-range= 117/2

Mid-range= 58.5 pounds

Answer:

[tex]\boxed{(x+7)^2 =-3x^2-14x}[/tex]

Step-by-step explanation:

[tex]4x^2 + 28x + 49 = 0[/tex]

[tex]\sf Subtract \ 3x^2 \ and \ 14x \ from \ both \ sides.[/tex]

[tex]4x^2 + 28x + 49 -3x^2-14x= 0-3x^2-14x[/tex]

[tex]x^2 + 14x + 49 = -3x^2-14x[/tex]

[tex]\sf Factor \ left \ side \ of \ the \ equation.[/tex]

[tex](x+7)^2 =-3x^2-14x[/tex]

Answer:

(x+7)² = -3x² -14x

Step-by-step explanation:

4x^2 + 28x + 49 = 0

Subtract 3x² and 14x from each sides.

x^2 + 14x + 49 = -3x² -14x

Next step will be factoring.

(x+7)² = -3x² -14x

Answer:

The present value is  [tex]PV = \$ 396,987[/tex]

Step-by-step explanation:

From the question we are told that

   The  interest payment per year is  [tex]C = \$ 85[/tex]

    The principal payment is  [tex]P = \$ 1000[/tex]

     The  duration is  n =  8   years

      The  interest rate is  [tex]r = 10\% = 0.10[/tex]

The present value is  mathematically represented as

      [tex]PV = [ \frac{C}{r} * [1 - \frac{1 }{ (1 +r)^n} ] + \frac{P}{(1 + r)^n} ][/tex]

substituting values

      [tex]PV = [ \frac{85}{0.10} * [1 - \frac{1 }{ (1 +0.10)^8} ] + \frac{1000}{(1 + 0.10)^ 8} ][/tex]

      [tex]PV = \$ 396,987[/tex]

Answer:

Complement = 15 Degrees

Supplement = 105 Degrees

Step-by-step explanation:

The complement of an angle refers to the measure that will make the angle 90 degrees.  So, the complement of 75 would be 15, since 90 - 75 = 15.

The supplement of an angle refers to the measure that will make the angle 180 degrees.  So, the supplement of 75 would be 105, since 180-75 = 105.

Cheers.

Answer:

300 SF

Step-by-step explanation:

just took the test

Answer:

The value for the Chi -square  test statistics = 1.149

Step-by-step explanation:

The observed value Table can be shown better as:

Observed Value

Age            Favorable          Unfavorable            Neutral              Total

18-30             67                            24                       20                   111

30-45            50                            14                        16                    80

Over 45         69                           21                        26                   116

Total              186                         59                        62                   307

NOTE: when computing the question, in the third row and the second column, there is a mistake , the value is supposed to be 21 and not  41 because :

69 +21+ 26 will eventually give = 116

69 + 41 + 26 = 136  

With that error being fix , let's get started.

Expected Value

The expected value can be determined by using the formula:

[tex]Expected \ Value = \dfrac{ row \ total \times column \ total }{grand \ total }[/tex]

For 67; (111 * 186)/307 = 67.251

For 24 : (111 * 59)/307 = 21.332

For 20 : (111 * 62)/307 = 22.417

For 50 :(80*186)/307 = 48.469

For 14 : (80* 59)/307 = 15.375

For 16 : ( 0 * 62)/307 = 16.156

For 69 : (116 * 186)/307 = 70.280

For 21 : (116* 59)/307 = 22.293

For 26 : (116*62)/307 = 23.427

Expected Value :

Age            Favorable          Unfavorable            Neutral              Total

18-30         67.251                 21.332                     22.417                  111

30-45        48.469                15.375                     16.156                  80

Over 45    70.280                22.293                     23.427               116

Total              186                         59                        62                   307

The Chi - square test statistics = [tex]\dfrac{(observed \ value - Expected \ value)^2}{Expected \ value}[/tex]

For 67.251 : ( 67 - 67.251)²/67.251 = 0.0009

For 21.332 : ( 24 - 21.332)²/21.332 = 0.3337

For 22.417 : ( 20 - 22.417)²/ 22.417 = 0.2606

For 48.469 : ( 50 - 48.469)²/ 48.469 = 0.0484

For 15.375 : ( 14 - 15.375)²/ 15.375 = 0.1230

For 16.156 : ( 16 - 16.156)²/ 16.156 = 0.0015

For 70.280 : ( 69 - 70.280)²/ 70.280 = 0.0233

For 22.293 : ( 21 - 22.293)²/ 22.293 = 0.0750

For 23.427 : ( 26 - 23.427)²/ 23.427 = 0.2826

The chi square table is as follows:

Age            Favorable          Unfavorable            Neutral          Total

18-30          0.0009              0.3337                   0.2606           0.5952

30-45         0.0484               0.1230                   0.0015            0.1729

Over 45     0.0233               0.0750                  0.2826            0.3809

Total          0.0726                0.5317                   0.5447              1.149

The value for the Chi -square  test statistics = 1.149

Answer:

15x - y = - 126

or y = 15x + 126

Step-by-step explanation:

will make it simple and short

to find the equation... we need to find slope first.

                   y2 - y1             -9  -   6

slope = m  = ---------    =       -----------  =  15

                   x2 - x1             -9  -  (-8)

so we know that the equation of the line using point (-8,6) and slope 15             y - 6 = 15( x + 8)

y - 6 = 15x + 120

Writing the equation in the form   Ax + By = C

15x - y = -120-6

therefore.... 15x - y = - 126   or simplify it as or y = 15x + 126

Hope this helps

Answer:

(3,-1)

Step-by-step explanation:

Graph boths functions (picture below)

Answer:

-11

Step-by-step explanation: