The first digit in any number must be 1, 2, 3, 4, 5, 6, 7, 8, or 9 because we do not write numbers such as 15 as 015. While it is reasonable to think that for most real-life data each digit occurs with equal frequency so that each digit 1, 2, ..., 9 has probability 1/9 of being the first digit, this is not true. It is a surprising phenomenon that in many naturally occurring numbers and web-based data the first digit has a probability distribution known as Benford's law.
Benford's law, also called the first-digit law, states that in lists of numbers from many (but not all) real-life sources of data, the leading digit is distributed in a specific, non-uniform way.
Specifically, for d = 1, 2, 3, 4, 5, 6, 7, 8, 9, Benford's law states P(first digit is d) = log_10(1+(1/d)) . The distribution of the first digit according to Benford's law, calculated to 3 decimal places, is shown in the table below.
Benford's law
First Digit X 1 2 3 4 5 6 7 8 9
Probability .301 .176 .125 .097 .079 .067 .058 .051 .046
Benford's Law and the Equally Likely Model benford equally likely
The law is named after physicist Frank Benford, who stated it in 1938, although it had been previously stated by Simon Newcomb in 1881. A surprising variety of data from the natural sciences, social affairs, and business obeys Benford's law.
This result has been found to apply to a wide variety of data sets, including electricity bills, street addresses, stock prices, population numbers, death rates, lengths of rivers, physical and mathematical constants, and processes described by power laws (which are very common in nature).
Numbers that are assigned, such as social security numbers and zip codes, or data with a fixed maximum, such as deductible contributions to individual retirement accounts, or randomly generated numbers, do not follow Benford's law.
The figure below shows how the distribution of the first digit of various naturally occurring and web-based data compares with Benford's law.
benford natural data web data
Figure information. Earthquakes: depth in km of 248,915 quakes, 1989-2009; source National Earthquake Information Center, United States Geological Survey. Minnesota lakes: size in acres of approx. 1100 lakes; source Wikipedia. Births: number of births in each county of the United States (approximately 3200), 2010; source: US Census Bureau. Diggs: total number of diggs for each of the top 1000 diggers at digg.com; source: socialblade.com.
Question 1:
(1a). What is the expected value of the first digit when the first digit follows Benford's law?
expected value (Use 3 decimal places).
(1b). What is the expected value of the first digit when the possible first digits are equally likely?
expected value (Use 3 decimal places).
(1c). What is the standard deviation of the first digit when the first digit follows Benford's Law?

Steps:

All cans take on the shape of a cylinder, unless you have seen interesting shape of cans like a starfish.

The formula for surface area of a cylinder is

SA = 2πr2 + 2πrh

where:

r = radius

h = height

Since we know the surface area and height, we can plug them in.  Note that we can factor out the 2π.  You will see why we factor out 2π rather than 2πr.

2π(r2 + (20)r) = 396

2π(r2 + 20r) = 396

Divide both sides of the equation by 2π to isolate the r terms.

r2 + 20r = 63.025    

Subtract 63.025 on both sides of the equation.

r2 + 20r - 63.025 = 0

Use the quadratic formula to solve for r:

r = (-b ± √(b2 - 4ac)) / 2a

where:

a = 1

b = 20

c = -63.025

Plug in these values into the formula.  You should get two solutions because of the plus/minus sign.  Accept the positive value of r.

Please mark brainliest

Hope this helps.

Answer:

53

Step-by-step explanation:

Plugging in 32 for z, you get:

(32)/2+37=x

16+37=x

x=53

Hope this helps!

The solution of the linear equation z/2 + 37 = x at x at z = 32 will be 53.

The distribution of weights to the variables involved that establishes the equilibrium in the calculation is referred to as a result.

A relationship between two or more parameters that, when shown on a graph, produces a linear model. The degree of the variable will be one.

The linear equation is given below.

z/2 + 37 = x

Then the solution of the linear equation z/2 + 37 = x at z = 32. Then the equation will be

x = 32/2 + 37

x = 16 + 37

x = 53

Thus, the solution of the linear equation z/2 + 37 = x at z = 32 will be 53.

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Answer:

[tex] \sqrt{3} - 1[/tex]

Step-by-step explanation:

[tex](1 + \sqrt{3} )(2 - \sqrt{3} ) \\ 2 - \sqrt{3} + 2 \sqrt{3} - 3 \\ = \sqrt{3} - 1[/tex]

Answer:

Increase the area of the deck by 12 square feet.

Step-by-step explanation:

The area of the deck increased by 12 square feet.

Area is the amount of space occupied by a two-dimensional figure. In other words, it is the quantity that measures the number of unit squares that cover the surface of a closed figure. The standard unit of area is square units which is generally represented as square inches, square feet, etc.

Given that, Chris is constructing a diagram for a deck he is restructuring in his backyard.

The deck will be in the shape of a square, and he has labeled a side length with the equation below, where x represents the original deck area. Side length = V1 + 12

Increase the area of the deck by 12 square feet.

Therefore, the area of the deck increased by 12 square feet.

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Answer:

The answer would be 5 and -12

Answer:

  -7

Step-by-step explanation:

To find the differences in a sequence, subtract the term before:

  -15 -(-8) = -7

  -22 -(-15) = -7

These differences are the same, so constitute the "common" difference.

The common difference of the sequence is -7.

Answer:

[tex] m =\frac{1098.56-694.55}{8-5}= 134.67[/tex]

And we can find the intercept like this:

[tex] 694.55 = 134.67*5 +b[/tex]

[tex] b = 694.55 -673.35= 21.2[/tex]

And the equation would be given by:

[tex] C = 134.67 w + 21.2[/tex]

Step-by-step explanation:

For this case we want a function given by:

[tex] C = mw +b[/tex]

Where C is the cost, m the slope, w the weight and b the intercept.

We have the following info (w=5, C= 694.55) and (w=8, C=1098.56) and we can find the slope with this formula:

[tex] m =\frac{1098.56-694.55}{8-5}= 134.67[/tex]

And we can find the intercept like this:

[tex] 694.55 = 134.67*5 +b[/tex]

[tex] b = 694.55 -673.35= 21.2[/tex]

And the equation would be given by:

[tex] C = 134.67 w + 21.2[/tex]

A linear function is a function that changes at a constant rate.

The formula of the linear relationship is [tex]C = 134.67w + 21.2[/tex]

The given parameters are:

Start by calculating the slope (m)

[tex]m = \frac{C_2 - C_1}{w_2 - w_1}[/tex]

This gives

[tex]m = \frac{1098.56 - 694.55 }{8- 5}[/tex]

Simplify

[tex]m = \frac{404.01}{3}[/tex]

This gives

[tex]m = 134.67[/tex]

The equation is then calculated as:

[tex]C = m(w -w_1) + w_1[/tex]

This gives

[tex]C = 134.67(w -5) + 694.55[/tex]

Expand

[tex]C = 134.67w -673.35 + 694.55[/tex]

[tex]C = 134.67w + 21.2[/tex]

Hence, the formula of the linear relationship is [tex]C = 134.67w + 21.2[/tex]

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Answer:

Solve for  

w

by simplifying both sides of the equation, then isolating the variable.

Exact Form:

w

=

49

2

Decimal Form:

w

=

24.5

Mixed Number Form:

w

=

24

Answer:

24

Step-by-step explanation:

Step-by-step explanation:

S.i =principal x rate x time/100

7,50000x4x4.5/100

13500000/100

135000

Answer:

The velocity is v(t) = 2*t + a

a) we want to find the average velocity betwen t = 0 and t = 1.

We can do this as:

Average = (v(1) + v(0))/2 = (2*1 + a + 2*0 + a)/2 = 1 + a

b) now we want to find the total distance traveled in the time lapse from t = 0 to t = 4.

For this we can see the integral:

[tex]d = \int\limits^4_0 {2*t + a} \, dt = 4^2 + a*4 - 0^2 - a*0 = 4^2 + a*4 = 16 + a^2[/tex]

Answer:

8.32 × 10^4

Step-by-step explanation:

The formula for the area of a triangle is 1/2×b×h.

1/2(320)(520) = 83,2000

83,200 in scientific notation is 8.32 × 10^4

Answer:

Terrance is 25.5

Step-by-step explanation:

Answer:

Hello There. The correct answer is 26

T = 3.5 + 22.5 = 26

Hope It Helps!

Answer:

The answer is D.

Step-by-step explanation:

You have to apply Indices Law,

[tex] { ({a}^{m}) }^{n} \: ⇒ \: {a}^{mn} [/tex]

So for this question :

[tex] { ({6}^{7}) }^{3} [/tex]

[tex] = {6}^{7 \times 3} [/tex]

[tex] = {6}^{21} [/tex]

Answer:

[tex]P(X>1600)=P(\frac{X-\mu}{\sigma}>\frac{1600-\mu}{\sigma})=P(Z>\frac{1600-1518}{325})=P(z>0.252)[/tex]

And we can find this probability using the z score formula and the complement rule and we got:

[tex]P(z>0.252)=1-P(z<0.252) =1-0.599= 0.401 [/tex]

[tex] z =\frac{1600-1518}{\frac{325}{\sqrt{81}}}= 2.27[/tex]

And we can find this probability using the z score formula and the complement rule and we got:

[tex]P(z>2.27)=1-P(z<2.27) =1-0.988=0.012[/tex]

Step-by-step explanation:

Let X the random variable that represent the SAT scores of a population, and for this case we know the distribution for X is given by:

[tex]X \sim N(1518,325)[/tex]  

Where [tex]\mu=1518[/tex] and [tex]\sigma=325[/tex]

We want to find this probability:

[tex]P(X>1600)[/tex]

And we can use the z score formula given by:

[tex]z=\frac{x-\mu}{\sigma}[/tex]

Using this formula we got:

[tex]P(X>1600)=P(\frac{X-\mu}{\sigma}>\frac{1600-\mu}{\sigma})=P(Z>\frac{1600-1518}{325})=P(z>0.252)[/tex]

And we can find this probability using the z score formula and the complement rule and we got:

[tex]P(z>0.252)=1-P(z<0.252) =1-0.599= 0.401 [/tex]

For the other part we need to take in count that the distribution for the sampel mean if the sample size is large (n>30) is given by:

[tex]\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})[/tex]

And we can use the z score formula given by:

[tex]z=\frac{x-\mu}{\frac{sigma}{\sqrt{n}}}[/tex]

And replacing we got:

[tex] z =\frac{1600-1518}{\frac{325}{\sqrt{81}}}= 2.27[/tex]

And we can find this probability using the z score formula and the complement rule and we got:

[tex]P(z>2.27)=1-P(z<2.27) =1-0.988=0.012[/tex]

Answer:

isosceles triangle

Step-by-step explanation:

Answer:

C

Step-by-step explanation:

-3x+4y=-12

Add 3x to both sides:

4y=3x-12

Divide both sides by 4 to isolate y:

y=3/4x-3

This means that the line described has a slope of 3/4 and a y intercept of -3. The only graph that matches this is choice C. Hope this helps!

Answer: c

Step-by-step explanation:

Answer:

$9400

Step-by-step explanation:

1.5x4=6%

100-6=94

0.94x10000=9400

Answer:

[tex]x = - 8[/tex]

Second answer is correct

Step-by-step explanation:

[tex] - 4(2x + 3) = 2x + 6 - (8x + 2) \\ - 8x - 12 = 2x + 6 - 8x - 2 \\ - 8x - 12 = - 6x + 4 \\ - 8x + 6x = 12 + 4 \\ - 2x = 16 \\ \frac{ - 2x}{ - 2} = \frac{16}{ - 2} \\ x = - 8[/tex]

hope this helps

Answer:

Step-by-step explanation:

Your answer would be 1/2.

Because they are 2 coins and each have a probability of landing on tails.

The probability that both display tails are 1/2.

We have given that,

Two fair coins are flipped at the same time

We have to determine the, what is the probability that both display tails.

Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speaking, 0 indicates the impossibility of the event and 1 indicates certainty.

Because they are 2 coins and each has a probability of landing on tails.

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Answer:

1:3

Step-by-step explanation:

divide 4 ...............

.............

ps: idk the explanation

Answer:

c

Step-by-step explanation:

you should divide the distance on time

so

33/6=5.5

26/4=6.5

60/8=7.5

17/2=8.5

you can see answer in this order in c

Answer:

Answer:

c

Step-by-step explanation:

you should divide the distance on time

so

33/6=5.5

26/4=6.5

60/8=7.5

17/2=8.5

you can see answer in this order in c

Step-by-step explanation:

Answer:

0-19: Make it 4 units tall

20-39: Make it 2 units tall

40-59: Make it 5 units tall

60-79: Make it 3 units tall

80-99: Make it 1 unit tall

Step-by-step explanation:

0-19: 4, 6, 19, 19 (4 numbers)

20-39: 29, 38 (2 numbers)

40-59: 40, 41, 41, 57, 58 (5 numbers)

60-79: 62, 66, 73 (3 numbers)

80-99: 87 (1 number)

Answer:

[tex]z=\frac{0.53 -0.81}{\sqrt{\frac{0.81(1-0.81)}{861}}}=-20.943[/tex]  

The p value would be given by:

[tex]p_v =P(z<20.943)\approx 0[/tex]  

The p value is a very low value compared to the significance level given so then we have enough evidence to reject the null hypothesis and we can conclude that the true proportion is significantly less than 0.81

Step-by-step explanation:

Info given

n=861 represent the random sample

[tex]\hat p=0.53[/tex] estimated proportion of people who responded play on a pc computer

[tex]p_o=0.81[/tex] is the value that we want to test

[tex]\alpha=0.05[/tex] represent the significance level

z would represent the statistic

[tex]p_v[/tex] represent the p value

Hypothesis to test

We want to verify if the true proportion decreases from 81%, the system of hypothesis are.:  

Null hypothesis:[tex]p\geq 0.81[/tex]  

Alternative hypothesis:[tex]p < 0.81[/tex]  

The statistic is given by:

[tex]z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}[/tex] (1)  

Replacing the info given we got:

[tex]z=\frac{0.53 -0.81}{\sqrt{\frac{0.81(1-0.81)}{861}}}=-20.943[/tex]  

The p value would be given by:

[tex]p_v =P(z<20.943)\approx 0[/tex]  

The p value is a very low value compared to the significance level given so then we have enough evidence to reject the null hypothesis and we can conclude that the true proportion is significantly less than 0.81

Answer:

x=3

Step-by-step explanation:

4x^2 - 36 = 0

Add 36 to each side

4x^2 -36 +36 = 0+36

4x^2 = 36

Divide each side by 4

4x^2/4 =36/4

x^2 = 9

Take the square root of each sdie

sqrt(x^2) = ±sqrt(3)

x = -3,+3

We want the positive square root

x=3

Answer:

A = 1/2 b*h

A = 24

b = 8

h = ?

24 = 1/2 * 8 * h

24 = 4h

h = 6

The height is 6 cm.

Hope this helps.

Answer:

The area of a trapezoid is 1/2 (b₁ + b₂) * h where b₁ and b₂ are the bases and h is the height. The answer is 1/2 * (3 + 4) * 1 = 3.5.

Answer:

[tex]1<x<3[/tex]

Step-by-step explanation:

Let simplify each of these inequalities individually and then look at where they intersect afterwards

[tex]x+1<4\\\\x<3[/tex]

And

[tex]x-8>-7\\\\x>1[/tex]

This means that for these two inequalities to intersect, x must be greater than 1, but less than 3.

This can be represented by the following inequality [tex]1<x<3[/tex]

Answer:

Answers below

Step-by-step explanation:

a. What was the sample size for this poll?

b. Are the data categorical or quantitative?

c. Would it make more sense to use averages or percentages as a summary of the data for this question?

d. Of the respondents, 67% said Yes, they would want it to pass. How many individuals provided this response?

Answer:

Step-by-step explanation:

There are no factors outside the parentheses that need to be distributed, so the parentheses can be simply dropped:

  6 -2x +15 -3x

The terms can be rearranged to put like terms next to each other:

  -2x -3x +6 +15

and the like terms can be combined.

  -5x +21 . . . . simplified expression

__

Put the value of x where x is, then do the arithmetic.

  -5(-0.2) +21 = 1 +21 = 22