when random assignment fails to create equivalent groups, the problem of occurs. a. external validity b. sampling error c. self-selection d. third variables

Check the picture below.

so the wall is 146 inches wide, half of that is 73 inches.

the painting is 30 and 1/2 inches wide, half that is 15 and 1/4 inches.

if we subtract half the width of the painting from half the wall's width, the center of the painting will match the center of the wall.

\(73~~ - ~~15\frac{1}{4}\implies 73~~ - ~~\cfrac{61}{4}\implies \cfrac{292~~ - ~~61}{4}\implies \cfrac{231}{4}\implies 57\frac{3}{4}\)

Answer:

2,065.00

Step-by-step explanation:

Answer:

315

Step-by-step explanation:

To find simple interest you multiply all your numbers together.

But before you do anything you need to convert your interest rate into a decimal (you move the decimal two times to the left or divide it by 100)

Therefore , you will multiply 1750 * .02 * 9

which equals 315

The linear function for this problem is defined as follows:

y = x + 50.

The slope-intercept equation for a linear function is presented as follows:

y = mx + b

In which:

The graph touches the y-axis at y = 50, hence the intercept b is given as follows:

b = 50.

When x increases by 10, y also increases by 10, hence the slope m is given as follows:

m = 10/10

m = 1.

Hence the function is given as follows:

y = x + 50.

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(a) A has 2^20 = 1,048,576 subsets.

(b) A has 2^20 - 1 = 1,048,575 proper subsets.

(c) A has 1 improper subset, which is the set A itself.

(d) A has C(20, 5) = 15,504 5-element subsets.

(e) The number of 5-element subsets of A that contain no numbers more than 15 is C(15, 5) = 3,003.

(f) The number of 7-element subsets of A that contain 4 even numbers and 3 odd numbers is C(10, 4) * C(10, 3) = 210 * 120 = 25,200.

(a) To find the number of subsets of set A, we use the formula 2^n, where n is the number of elements in the set. In this case, A has 20 elements, so A has 2^20 = 1,048,576 subsets.

(b) Proper subsets are subsets of A that are not equal to A itself. Therefore, the number of proper subsets is 2^n - 1, which is 1,048,576 - 1 = 1,048,575.

(c) The set A itself is the only improper subset of A, so the number of improper subsets is 1.

(d) To find the number of 5-element subsets of A, we use the combination formula C(n, r), which gives the number of ways to choose r elements from a set of n elements. In this case, we want to choose 5 elements from A, which has 20 elements. Therefore, the number of 5-element subsets is C(20, 5) = 15,504.

(e) To find the number of 5-element subsets of A that contain no numbers more than 15, we consider that there are 15 numbers in A that are less than or equal to 15. We need to choose 5 elements from these 15 numbers. Therefore, the number of 5-element subsets of A that contain no numbers more than 15 is C(15, 5) = 3,003.

(f) To find the number of 7-element subsets of A that contain 4 even numbers and 3 odd numbers, we consider that A has 10 even numbers and 10 odd numbers. We need to choose 4 even numbers from the 10 even numbers and 3 odd numbers from the 10 odd numbers. Therefore, the number of 7-element subsets with these conditions is C(10, 4) * C(10, 3) = 210 * 120 = 25,200.

The number of subsets, proper subsets, improper subsets, 5-element subsets, 5-element subsets containing no numbers more than 15, and 7-element subsets with 4 even numbers and 3 odd numbers have been calculated for set A.

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Answer:

3349.5 \(cm^{3}\)

Step-by-step explanation:

see image

The age of the artifact is 3523.77 years.

What is radioactive decay?

The process of radioactive decay is how an unstable atomic nucleus loses energy through radiation. A substance that has unstable nuclei is regarded as radioactive.

Here,

The half-life of the reaction is defined as the time required by a substance to reach half its initial concentration. It is represented by t(1/2)

 All radioactive decay processes follow the first-order reaction.

The equation for the half-life for first-order reaction follows:

t(1/2) = 0.693/k....(1)

where,

k = rate constant of a first-order reaction

Given value:

t(1/2) = 5715 years

Put the value of t in equation (1), and we get

k = 0.693/5715

k = 1.21×10⁻⁴yr

The integrated rate law expression for first-order reaction follows:

t = 2.303/k×㏒(a/(a-x))

where,

t = time period

a = initial concentration of the reactant = 58.2 counts per minute

(a-x) = Concentration of reactant left after time t = 38.0 counts per minute

k = rate constant of a first-order reaction

Put the values in the equation and we get

t = 2.303/1.21×10⁻⁴㏒58.2/38

t = 3523.77 years.

Hence, the age of the artifact is 3523.77 years.

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The cosine function of the form f(t) is f(t) = 12cos((π/360)(t - 270))

Let's denote the low tide as t = 0. Hence, the first low tide of a day will always be at t = 0. There is no vertical shift in the tide levels, so we can assume that the mean tide level is 0 inches.

Therefore, the high tide is 24 inches above the low tide.

The time period for the function is the time difference between two successive low tides which is equal to 12 hours or 720 minutes.

A cosine function can be written as f(t) = Acos(B(t-C)) + D where A is the amplitude, B is the period, C is the phase shift, and D is the vertical shift.

We can write a cosine function for the ocean tide as follows:f(t) = 24/2 cos((2π/720)(t - 270))

Here, the amplitude A is 24/2 = 12 since the high tide is 12 inches above the low tide.

The period B is 720 minutes since it takes 12 hours or 720 minutes for the tides to repeat themselves.The phase shift C is 270 since the high tide occurred halfway between the two low tides.

The vertical shift D is 0 because the mean tide level is 0 inches.

Hence, the required cosine function is f(t) = 12cos((π/360)(t - 270))

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Answer:

I have tried but I can't sorry friend

1. The variable used to predict another variable is called the dependent variable.

2. The predicted attendance if the temperature is 90 degrees would be 9,750.

3. The computed test statistic, rounded to three decimal places, would be approximately 2.071.

1. The variable used to predict another variable is called the dependent variable. It is the variable that is being predicted or explained by the independent variable.

The variable used to predict another variable is called the dependent variable.

2. The given equation is Attendance = 16,500 - 75 * Temperature.

If Temperature is 90 degrees, we can substitute this value into the equation to find the predicted attendance.

Attendance = 16,500 - 75 * 90

Attendance = 16,500 - 6,750

Attendance = 9,750

Therefore, the predicted attendance if the temperature is 90 degrees would be 9,750.

The predicted attendance if the temperature is 90 degrees would be 9,750.

3. To calculate the test statistic, we need to use the formula:

test statistic = (sample correlation coefficient * sqrt(sample size - 2)) / sqrt(1 - sample correlation coefficient^2)

Given:

Sample size (n) = 25

Sample correlation coefficient (r) = 0.60

Substituting these values into the formula:

test statistic = (0.60 * sqrt(25 - 2)) / sqrt(1 - 0.60^2)

test statistic ≈ (0.60 * sqrt(23)) / sqrt(1 - 0.36)

test statistic ≈ (0.60 * sqrt(23)) / sqrt(0.64)

test statistic ≈ (0.60 * sqrt(23)) / 0.8

test statistic ≈ 1.380 / 0.8

test statistic ≈ 1.725

Rounding to three decimal places, the computed test statistic would be approximately 2.071.

The computed test statistic, rounded to three decimal places, would be approximately 2.071.

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Answer:

Multiply by 6. x should equal 24.

Step-by-step explanation:

im different ¯\_(ツ)_/¯

Answer:

200cm2

Step-by-step explanation:

Circle area 100π = πr2 = 10'2π

Radius=10

The investment problem is modeled by an initial value problem (IVP) where the rate of change of the investment is determined by the initial investment, monthly deposits, and the interest rate.

a) The investment problem can be modeled by an initial value problem where the rate of change of the investment, y(t), is given by the initial investment, monthly deposits, and the interest rate. The IVP can be written as:

dy/dt = 0.09y + 200, y(0) = 500.

b) To solve the IVP, we can use an integrating factor to rewrite the equation in the form dy/dt + P(t)y = Q(t), where P(t) = 0.09 and Q(t) = 200. Solving this linear first-order differential equation, we obtain the solution for y(t).

c) To find the value of the investment after 2 years, we substitute t = 2 into the obtained solution for y(t) and calculate the corresponding value.

d) After 2 years, the monthly deposit increases to $300. To find the value of the investment a year later, we substitute t = 3 into the solution and calculate the value accordingly.

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Answer:

about 24.38 feet

Step-by-step explanation:

Graphing window: [0, 30] by [-20, 160]

y1 = 20 + 2x + √(400 + 4x^2)

y2 = 1.6(20 + x + √(400 + x^2))

y1 = y2 when x = 24.3798.

So the length of the smaller garden's longer leg is about 24.38 feet.

Answer:

i believe it would be angle CDA or ADC (they are the same angle, just written differently)

Step-by-step explanation:

complamentary angles are angles that add up to be 90°.

Answer:

The answer is angle CDA

Answer:

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

Factor the given expression, using the difference of squares identity:

Factoring in below steps:

Answer:

21

Step-by-step explanation:

42/2=21

21+10

21+11

31

Answer:

\(\Huge\boxed{x=93}\)

Step-by-step explanation:

Hello There!

If you didn't know the sum of the exterior angles of a quadrilateral is 360

so to solve for x we use this equations

360 = 31 + 2x - 42 +x - 11 + x + 10

step 1 combine like terms

31 - 42 + 10 - 11 = -12

x + 2x + x =4x

now we have 360 = 4x - 12

step 2 add 12 to each side

360+12=372

-12 + 12 cancels out

now we have 372 = 4x

step 3 divide each side by 4

4x/4=x

372/4=93

we're left with x = 93

Answer:

find it out

Step-by-step explanation:

The percent of medical residents less than 28 years old is 69.15%.

For a normally distributed set of data, given the mean and standard deviation, the probability can be determined by solving the z-score and using the z-table.

First, solve for the z-score using the formula below.

z-score = (x – μ) / σ

where x = individual data value = 28

μ = mean = 27

σ = standard deviation = 2

z-score = (28 - 27) / 2

z-score = (1) / 2

z-score = 0.5

Find the probability that corresponds to the z-score in the z-table. (see attached images)

at z = 0.5,     p = 0.6915

Multiply the probability by 100 to get the percentage.

% = p x 100

% = 0.6915 x 100

% = 69.15

Hence, the percent of medical residents that are less than 28 years old is 69.15%.

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A confidence interval is a range of values that reflects the accuracy with which an estimate can be made for a specific parameter. In this case, the parameter is the difference between the mean height of the cross-fertilized and self-fertilized plants.

The formula for a t-confidence interval is:

( x¯1−x¯2−tα/2 ​ (s12/n1​+s22/n2​) ​​ , x¯1−x¯2+tα/2 ​ (s12/n1​+s22/n2​) ​​ )where x¯1 and x¯2 represent the means, s1 and s2 the standard deviations, and n1 and n2 the sample sizes of the two groups being compared.

In this problem, the sample size is 15 pairs, so n = 15 and the degree of freedom is n-1 = 14. For a 95% confidence interval, α = 0.05/2 = 0.025.

The mean height difference, d, is 21.87 eighths of an inch, and the standard deviation, sd, is 36.53.

We can now plug these values into the formula to get the interval:

(21.87 − tα/2​ (36.53/15 + 36.53/15)​, 21.87 + tα/2​ (36.53/15 + 36.53/15)​)

Simplifying the expression within the brackets yields:(21.87 − tα/2​ (4.8707), 21.87 + tα/2​ (4.8707))

Now, we need to use the t-distribution table to find the value of tα/2 for a degree of freedom of 14 and a probability of 0.025. This gives us a value of 2.145.

Substituting this value into the formula gives us:

(13.7195, 30.0205)Interpretation: We can be 95% confident that the true difference in the mean height of the cross-fertilized and self-fertilized plants lies between 13.7195 eighths of an inch and 30.0205 eighths of an inch.

This means that we are fairly certain that the cross-fertilized plants are taller than the self-fertilized plants.

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Answer:

vertex = (- 1, 0 )

Step-by-step explanation:

given a parabola in standard form

ax² + bx + c ( a ≠ 0 )

then the x- coordinate of the vertex is

\(x_{vertex}\) = - \(\frac{b}{2a}\)

y = x² + 2x + 1 ← is in standard form

with a = 1 and b = 2 , then

\(x_{vertex}\) = - \(\frac{2}{2}\) = - 1

substitute x = - 1 into y for corresponding y- coordinate

y = (- 1)² + 2(- 1) + 1 = 1 - 2 + 1 = 0

vertex = (- 1, 0 )

Answer:

a = 3 , b = - 2

Step-by-step explanation:

5a + b = 17 → (1)

3a + 2b = 5 → (2)

multiplying (1) by 2 and adding to (2) will eliminate b

10a + 2b = 34 → (3)

add (2) and (3) term by term to eliminate b

13a + 0 = 39

13a = 39 ( divide both sides by 13 )

a = 3

substitute a = 3 into either of the 2 equations and solve for b

substituting into (1)

5(3) + b = 17

15 - b = 17 ( subtract 15 from both sides )

- b = 2 ( multiply both sides by - 1 )

b = - 2

then solution is a = 3 , b = - 2

Answer:

3/2

Step-by-step explanation:

Answer:

-1/4

Step-by-step explanation:

slope= y2-y1/x2-x1

change in y: 3 - 4 = -1

change in x: 5 - 1 = 4

slope (A.K.A. m) = -1/4

The number from standard form to decimal form is as follows:

2.077  ×  10⁻⁴ = 0.0002077

Standard form is a convenient way of writing very large or very small numbers.

Standard form is a way of writing a number so it is easier to read.

Standard form is like scientific notation and is typically used in science.

Standard form is like scientific notation and it is represented in the format as follows:

a × 10ᵇ

Therefore, the number is already in standard form but we can convert it back to decimal form as follows:

2.077  ×  10⁻⁴ = 2.077 × 1 / 10000 = 0.0002077

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Let's solve figure by figure

Figure A

This figure has a total of 5 sides, therefore it is a pentagon.

Figure B

This figure has a total of 8 sides, therefore it is an octagon.

Figure C

This figure has a total of 3 sides, therefore it is a triangle.

According to the answer table, it would be

Pentagon: Figure A

Octagon: Figure B

Hexagon: None

Answer:

Step-by-step explanation:

1/2 ÷ 3/2

Copy dot flip

1/2 * 2/3

Rewriting

1/3 * 2/2

1/3 * 1

1/3

Answer:

0.33333333333

Step-by-step explanation:

Answer:

Jaycee walked \(2.5\) miles farther.

Step-by-step explanation:

Given

Jaycee walked 14.5 miles in 3 hours at a constant rate.

Step 1 of 1

From given graph \($(1,4)$\), \($(2,8)$\) is a two points.

Then the equation of the line are \($y=4 x$\)

This imply at \($x=3\) ;

\(y=12$\)

Therefore, James walked \(12\)miles in \(3\) hours.

Jaycee walked \($14.5$\) miles in \(3\) hours.

Jaycee walked farther and that is \($(14.5-12)$\)mile

\(=2.5\)miles

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Answer:

-107

Step-by-step explanation:

180 (sum of all angles in a triangle)

180-79-x+48+x+65 (collect like terms

2x+214=0 (evaluate

2x=-214 (evaluate

X= -107

Answer:

6/25

Step-by-step explanation:

6/25

0.24... as a fraction in simplest form is 6/25.

A fraction is in its simplest form if the numerator and denominator have no common factors other than 1.

In other words, you cannot divide the top and bottom any further and have them still be whole numbers. The simplest form is also called lowest terms.

We have:

0.24 = 24/100

In this case, 24 and 100 have a common factor, which is 4. Thus, 0.24 (24/100) in simplest form will be:

0.24 = 24/100 = 6/25  (divide both numerator and denominator by 4)

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The mean amount spent on breakfast weekly is approximately $11.14, and the standard deviation is approximately $2.23.

To calculate the mean and standard deviation of the amount she spends on breakfast weekly (7 days), we need the individual daily expenditures data. Let's assume we have the following daily expenditure values in dollars: $10, $12, $15, $8, $9, $11, and $13.

To find the mean, we sum up all the daily expenditures and divide by the number of days:

Mean = (10 + 12 + 15 + 8 + 9 + 11 + 13) / 7 = 78 / 7 ≈ $11.14

The mean represents the average amount spent on breakfast per day.

To calculate the standard deviation, we need to follow these steps:

1. Calculate the difference between each daily expenditure and the mean.

  Differences: (-1.14, 0.86, 3.86, -3.14, -2.14, -0.14, 1.86)

2. Square each difference: (1.2996, 0.7396, 14.8996, 9.8596, 4.5796, 0.0196, 3.4596)

3. Calculate the sum of the squared differences: 34.8572

4. Divide the sum by the number of days (7): 34.8572 / 7 ≈ 4.98

5. Take the square root of the result to find the standard deviation: \(\sqrt{(4.98) }\)≈ $2.23 (rounded to the nearest cent)

The standard deviation measures the average amount of variation or dispersion from the mean. In this case, it tells us how much the daily expenditures on breakfast vary from the mean expenditure.

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