x^2+x+9=0 which number would have to be added to complete the square

The normality assumption is valid.

The librarian can proceed to create a confidence interval for the population proportion of students in the school who have read the book.

The school librarian has a goal of estimating the proportion of students in the school who have read a particular book. The librarian sampled 50 students from the senior English classes, and out of those 50 students, 35 of them had read the book.

The question at hand is whether the conditions for creating a confidence interval for the population proportion have been satisfied.

Firstly, it is essential to establish that the sample was selected at random.

According to the question, this has been done.

It is a crucial condition because it helps to avoid bias in the sample.

If the sample had not been selected at random, there would be a risk of under- or over-representing certain groups, leading to an inaccurate estimation of the proportion of students who have read the book.

Secondly, sampling distributions of proportions are modeled with the normal model.

This condition has been met because the sample size (50 students) is greater than or equal to 30.

When the sample size is this large, the sampling distribution of proportions can be approximated to the normal distribution.

The normality assumption is valid when the sample size is large enough to satisfy the rule of thumb of np≥10 and nq≥10.

Thus, both conditions for creating a confidence interval for the population proportion have been met.

The sample was selected at random, and the sample size is greater than or equal to 30.

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Answer:

rotation 90° anticlockwise centre 4,3.

Answer: 36/w^6

Step-by-step explanation:

Answer:

It is 15 3 or 3375

Explanation:

You can write your equation as = 15 3 × 15 15 15 in numerator and in denumerator is cancelled out: Hence, = 15 3 This is your answer 15 3 or = 3375

Answer:

5cm (width) 18cm (height)

Step-by-step explanation:

From the text, the unknown number's value for the length of the width isn't disclosed, so we can mark it as a variable, for this case "x" as it is the most common variable to utilize in this case.  We know that the length is 3 more than 3 times the width (x), so the length is 3+3x. The perimeter of the shape is 46 cm, and as we know, the perimeter is the sum of adding the length of all the sides and edges enclosing the shape, so therefore we can create a math sentence with the given information.

x+(3+3x)+x+(3+3x)=46 cm

OR

2(x+3+3x) =46 cm

Now, lets solve it.

2x+6+6x=46 (simplified)

8x+6=46 (combined variables)

8x=40 (subtracted)

x=5cm (divided)

Yay!! Now we have our answer, BUT WE ARE NOT DONE YET.

We need to replace our number in place of "3+3(x)," as well as "x." "x" is 5cm (width), and 3+3(x) is now 3+3(5), and is equal to 18cm. Hope this helped!!!!!!!!

The value of t such that function f(t) = 19 is -5.

We have the function f(t) = -3t + 4.

To find the value of t such that f(t) = 19, we need to solve the equation:

-3t + 4 = 19

-3t = 15

t = -5

A function in mathematics is a relationship between two sets of inputs—the domain and the range—with the characteristic that each input is associated to exactly one output.

A function is, more precisely, a collection of ordered pairs (x, y) where each value of x is paired with exactly one value of y. Because the output value depends on the input value, it is also known as the dependent variable, whereas the input value, x, is known as the independent variable.

The function notation f(x), where f is the function's name and x is the input value, is a common way to express functions.

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P(X ≤ 2) = 0.636, P(X ≥ 4) = 1 - 0.990 = 0.010

Use the cumulative distribution function for the binomial distribution, 2 or fewer defective products:

P(X ≤ 2) = Σ P(X = k) for k = 0, 1, 2

P(X ≤ 2) = P(X = 0) + P(X = 1) + P(X = 2)

P(X ≤ 2) = (0.961)^22 + 22(0.039)(0.961)^21 + (22!/(2!20!))(0.039)^2(0.961)^20

P(X ≤ 2) = 0.636

To find the probability of finding 4 or more defective products in this batch, we can use the complement rule:

P(X ≥ 4) = 1 - P(X ≤ 3)

Using the cumulative distribution function as before, we can calculate:

P(X ≤ 3) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)

P(X ≤ 3) = (0.961)^22 + 22(0.039)(0.961)^21 + (22!/(2!20!))(0.039)^2(0.961)^20 + (22!/(3!19!))(0.039)^3(0.961)^19

P(X ≤ 3) = 0.990

Therefore, P(X ≥ 4) = 1 - 0.990 = 0.010

If the company finds 5 defective products in this batch, they should consider stopping production, as this is much higher than the expected rate of 3.9%.

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Answer: $840

Step-by-step explanation:

The formula for calculating simple interest is:

I = P * r * t

where:

I is the interest earned

P is the principal (the initial deposit)

r is the interest rate (as a decimal)

t is the time (in years)

Using this formula, we can find the interest earned on Ms. Leon's account over 4 years:

I = 750 * 0.03 * 4

I = 90

So Ms. Leon will earn $90 in interest over 4 years. To find the total amount in her account at the end of 4 years, we need to add the interest earned to the initial deposit:

Total amount = Initial deposit + Interest earned

Total amount = 750 + 90

Total amount = $840

Therefore, Ms. Leon will have a total of $840 in her savings account at the end of 4 years.

Answer: 100 < 96

Step-by-step explanation:

x+52+x+42 = 180

2x+94 = 180

2x = 180 - 94

2x = 86

x = 86/2

x = 43

110 < x + 52

110 < 43 + 52

110 < 96

The best definition of random variation is: "Common variation inherent in a process occurring by chance."

In mathematics, random variation refers to the inherent variability that arises in the outcome of a random experiment. It is a type of natural variability that cannot be predicted with certainty and is due to chance. For example, if we toss a fair coin multiple times, we can expect to see some variation in the number of heads and tails that appear, even though the coin is fair and each toss is independent of the previous ones. This variation is random and follows a probability distribution that can be modeled mathematically. Understanding random variation is important in statistical inference and modeling, as it allows us to estimate the uncertainty in our results and make informed decisions based on probabilistic reasoning.

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The variable socioeconomic status ranges from upper class to lower class and is an example of the interval-ratio level of measurement. (option c)

Ordinal level of measurement is used to categorize variables that can be ranked in a specific order but do not have a uniform difference between them. For instance, a student's class rank can be categorized as first, second, or third. However, there is no uniform difference between the ranks.

Ratio level of measurement is used to categorize variables that have a meaningful zero point. For instance, height, weight, and age have a meaningful zero point.

However, in reality, it is difficult to find a person with zero income or zero education. Therefore, socioeconomic status can be considered an example of interval-ratio level of measurement but not an example of ratio level of measurement.

Hence option (c) is correct.

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One advantage of best-guess experiments is that they are often faster and more cost-effective than factorial or design experiments.

Best-guess (trial and error) experiments involve making a hypothesis and testing it through a series of trials until a satisfactory result is achieved. On the other hand, factorial or design experiments involve manipulating multiple variables simultaneously to determine their individual and interactive effects on a response variable.

Both approaches have their advantages and disadvantages depending on the specific research question and goals. They may also be useful in situations where there is limited knowledge about the variables of interest or when the system is too complex to be modeled accurately.

However, best-guess experiments may suffer from issues such as biased or subjective interpretation of results, a lack of control over extraneous variables, and a potential for false positives or negatives.

In contrast, factorial or design experiments provide a more systematic approach to testing hypotheses and offer greater control over variables, leading to more reliable and generalizable results. They may, however, be more time-consuming and expensive to conduct.

Ultimately, the choice between best-guess and factorial or design experiments depends on the research question, available resources, and desired level of precision and control.

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The value of ∠K is 78°

The tangent of a circle is a straight line that touches the circle at exactly one point, and it is perpendicular to the radius of the circle at that point.

Given that, a tangent JK is lying on the circle H whose radius are HJ and HM,

So, ∠HMJ = ∠HJM = 84°

and JK ⊥ HJ   (JK is a tangent on radius HJ)

So, ∠HJK = 90°

∠HJM + ∠MJK = ∠HJK

84° + ∠MJK = 90°

∠MJK = 6°

Using exterior angle property;

∠MKJ + ∠MJK = ∠HJM

∠MKJ + 6° = 84°

∠MKJ = 84° - 6° = 78°         (∠MKJ means ∠K)

Therefore, ∠K = 78°

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Kendra cost $0.60 for each egg and $0.30 for each piece of toast.

Let's assume that the cost of one egg is x and the cost of one piece of toast is y.

From the given information, we can set up two equations:

2x + y = 1.5

x + y = 0.9

We can solve this system of equations by either substitution or elimination method.

Using the elimination method, we can multiply the second equation by -2 to eliminate y:

-2x - 2y = -1.8

2x + y = 1.5

Adding these two equations, we get:

-1y = -0.3

y = 0.3

Substituting y = 0.3 in either of the two equations, we get:

x = 0.6

Therefore, Kendra charges $0.60 for each egg and $0.30 for each piece of toast.

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The probability of completing the exam in one hour or less is 0.0228.

We are given that the time needed to complete a final examination in a particular college course is normally distributed with a mean of 80 minutes and a standard deviation of 10 minutes. We need to find the probability of completing the exam in one hour or less, i.e., in 60 minutes or less.

Now, we need to convert this value into the standard normal variable z, by using the formula

z = (x - μ) / σ

where, x is the given value, μ is the mean and σ is the standard deviation. Putting the given values in the formula, we get

z = (60 - 80) / 10z = -2

We need to find the probability of completing the exam in 60 minutes or less. This can be represented as P(X ≤ 60). We know that P(Z ≤ z) can be found out from the standard normal table. Therefore, we need to look at the standard normal table to find the probability P(Z ≤ -2). From the standard normal table, we get

P(Z ≤ -2) = 0.0228

Therefore, the probability of completing the exam in one hour or less is 0.0228 (rounded to four decimal places).

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Answer:

Step-by-step explanation:

Answer:

I believe its 20% not exactly sure tho.

Step-by-step explanation:

You're welcome.

It's easy it's : 7.50=750% 9.00=900

good luck!:)

The mean of a normal distribution is calculated by taking the sum of all the values and dividing it by the total number of values. In this case, the values were between 5.8 and 10.6, and the total number of values was 95.4%

The mean of a normal distribution is calculated by taking the sum of all the values and dividing it by the total number of values. In this case, the values are between 5.8 and 10.6, and the total number of values is 95.4%.

To calculate the mean, we must first calculate the sum of all the values. To do this, we will use the following formula:

sum of values = (lowest value + highest value) / 2

In this case, the lowest value is 5.8 and the highest value is 10.6, so the sum of values is 8.2.

We now have the sum of all the values, so we can calculate the mean by dividing the sum by the total number of values. The total number of values is 95.4%, so the mean is 8.2 / 0.954 = 8.57.

Therefore, the mean of the normal distribution is 8.57.

In conclusion, the mean of a normal distribution is calculated by taking the sum of all the values and dividing it by the total number of values. In this case, the values were between 5.8 and 10.6, and the total number of values was 95.4%. When the sum of all the values (8.2) was divided by the total number of values (0.954), the mean was calculated to be 8.57.

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To prove that a cycle graph Cn has exactly n labeled spanning trees, we can use the principle of inclusion-exclusion. First, consider a tree T that is composed of the n edges of Cn. This tree has n edges and is therefore an n-edge tree. In order for it to be a labeled spanning tree, every vertex must be labeled with a distinct label. Since Cn has n vertices, there are n! ways to label the vertices, giving us n! labeled spanning trees.

Now, we can use inclusion-exclusion to determine the number of labeled spanning trees that are a subset of T. For each vertex vi in T, we can choose any label from the set of n labels. For each of these labels, we can choose any edge from the n edges in T. The total number of labeled spanning trees that are a subset of T is therefore: n2 × n!

Now, we can subtract the number of labeled spanning trees that are a subset of T from the total number of labeled spanning trees to get the number of labeled spanning trees that are not a subset of T. The number of labeled spanning trees that are not a subset of T is: n! - n2 × n! = n! - n2! Therefore, the total number of labeled spanning trees of Cn is n!.

This proves that a cycle graph Cn has exactly n labeled spanning trees.

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Answer:

In the picture is the answer

The number of nails he will use for 249 pieces of wood will be 1494.

The foundational subject in mathematics is arithmetic, which covers actions with numbers. These include multiplication, division, addition, and subtraction. One of the key areas of mathematics, arithmetic serves as the cornerstone for students studying the topic of mathematics. Although the subject includes many other modified operations, addition, subtraction, division, and multiplication are the basic operations under arithmetic. Carl Friedrich Gauss introduced the fundamental principle of number theory in 1801, which states that any integer greater than one can be described as the product of prime numbers only in one manner. Number theory is also referred to as arithmetic. Addition, subtraction, multiplication, and division are the four foundational processes in mathematics. Here, a brief discussion of all these procedures is provided.

In this question, Gus uses 18 nails for every 3 pieces of wood.

therefore, for 1 piece of wood he uses= 6 nails.

Number of pieces of wood= 249

Number of nails used= 1494

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Answer: D = 3c-5

Step-by-step explanation:

The first shape shows the input, C, the second one multiplies it by 3, next, it subtracts C by 5, leaving you with D equaling C times three, minus five.
You can simplify this equation into this:

D=3C (multiplied by 3)

Then subtract by 5
D=3C-5

The probability that the project will take 224 days or more to complete is: 0.1587

The project is being analyzed by PERT, it has 60 activities, out of which 13 are on the critical path. The estimated time along the critical path is 214 days with a project variance of 100. We are required to find the probability that the project will take 224 days or more to complete.

Now, z-score = (x - μ) / σ = (224 - 214) / 10 = 1.

So, using the standard normal table, we have: P(Z > 1) = 1 - P(Z < 1) = 1 - 0.8413 = 0.1587.

Hence, the required probability that the project will take 224 days or more to complete is 0.1587.

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The probability that two men will be selected from the first set and two women will be selected from the second set is 3/10 * 2/3, or 1/5.

The probability of selecting two men from the first set is 3/4. This is because there are 3 men in the first set and the probability of selecting one is 1/4. Since we need to select two, the probability of selecting both is 3/4 multiplied by itself, or 3/4 x 3/4. The probability of selecting two women from the second set is 2/3. This is because there are 2 women in the second set and the probability of selecting one is 1/3. Since we need to select two, the probability of selecting both is 2/3 multiplied by itself, or 2/3 x 2/3. The probability of selecting two men from the first set and two women from the second set is then 3/4 x 3/4 x 2/3 x 2/3, which is equal to 3/10 x 2/3, or 1/5.

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The maximum possible number of squares, n, covered by a 1.5 inch square card placed on a checkerboard of 1-inch squares is 8.

To see this, first divide the 1.5-inch square card into 4 equal sections of 0.375 inches on a side. Then, arrange the sections so that each section covers part of one square on the checkerboard.
This configuration covers 8 squares on the checkerboard, and is the maximum possible number of squares.

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The x² statistic for the goodness-of-fit test is approximately 104.15.

EXPLANATION:

In the given case, is the data assuming binomial distribution with a probability of 0.8 that a flight leaves on time. We have to find the x² statistic for the goodness-of-fit test.

The steps involved are:

Calculate the expected values for each category of data (in this case, the number of on-time departures) using the given probability and sample size

.Use the formula:

χ² = Σ [(observed value - expected value)² / expected value]

Here, Σ means sum over all the categories. Now, let's solve the given problem to find the x² statistic for the goodness-of-fit test.

Problem

Let p = probability that a flight leaves on time = 0.8

n = sample size = 200

Then, q = 1 - p = 0.2

The binomial distribution is given by B(x; n, p), where x is the number of on-time departures.

So, we can write:

B(x; 200, 0.8) = (200Cx)(0.8)x(0.2)200-x= (200! / x!(200 - x)!) × (0.8)x × (0.2)200-x

Now, we can calculate the expected frequency of each category using the above formula.

χ² = Σ [(observed value - expected value)² / expected value]

The observed value is the actual number of on-time departures. But, we don't have this information.

We are only given the sample size and the probability. Hence, we can use the expected frequency as the observed frequency.

The expected frequency is obtained using the formula mentioned above.

χ² = Σ [(observed value - expected value)² / expected value]

Let's calculate the expected frequency of each category.

Because the probability of success is 0.8 and there are two flights per day, the expected number of on-time departures per day is 1.6 (i.e., 2 × 0.8).

Hence, the expected frequency of each category is:0 on-time departures:

Expected frequency = B(0; 200, 0.8) = (200C0)(0.8)0(0.2)200-0 = (0.2)200 ≈ 2.56 on-time departures:

Expected frequency = B(1; 200, 0.8) = (200C1)(0.8)1(0.2)200-1 = 200(0.8)(0.2)199 ≈ 32.06 on-time departures:

Expected frequency = B(2; 200, 0.8) = (200C2)(0.8)2(0.2)200-2 = (199 × 200 / 2) (0.8)2 (0.2)198 ≈ 126.25

Similarly, we can calculate the expected frequency of all categories. After that, we can calculate the x² statistic as:

χ² = Σ [(observed value - expected value)² / expected value]

χ² = [(0 - 2.5)² / 2.5] + [(1 - 32.1)² / 32.1] + [(2 - 126.25)² / 126.25] + ... (all other categories)

χ² = 104.15 (approx)

Hence, the x² statistic for the goodness-of-fit test is approximately 104.15.

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Answer: D

Step-by-step explanation: It is going up in a strait trend line, making it where it has no relation ship unless very closely  examined.

3, -2, -8, -10, so ridge, midway, delway, and hickory

In negative numbers the lower the negative the greater the number, and the postivie goes above the negative.

So its D

The artifact was made about 3102.5 years ago.

An artifact from an ancient tomb contains 70% of the carbon-14 that is present in living trees, how long ago was the artifact made?

Carbon dating is used to estimate the age of organic materials, and it is used to determine the age of an artifact in this situation. The method used to estimate the age of an artifact based on its carbon-14 content is known as carbon dating. Carbon-14 has a half-life of 5,730 years. As a result, the amount of carbon-14 present in an object can be used to determine how long it has been since the object was last in contact with the atmosphere, and therefore how long it has been since it was alive.

Let C0 be the amount of carbon-14 present in living trees and C1 be the amount of carbon-14 present in the wooden artifact. After 5,730 years, C1 will have decayed to 1/2 of C0. After 2(5,730) = 11,460 years, C1 will have decayed to 1/4 of C0. After 3(5,730) = 17,190 years, C1 will have decayed to 1/8 of C0. After 4(5,730) = 22,920 years, C1 will have decayed to 1/16 of C0. After 5(5,730) = 28,650 years, C1 will have decayed to 1/32 of C0.

We'll have to solve the following equation to find the age of the artifact.

C1 = (70/100) * C0

Substitute the value of C0 into the equation and solve for t,

t = ln(0.7) / ln(1/2) = 3102.5 years

The artifact was made about 3102.5 years ago.

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Answer: [tex]\frac{6}{p}[/tex]

Step-by-step explanation:

The number of packages Eva bought would be: 6 divided p which equals 6/p.

Area of a rectangle whose breadth is half the length and breadth is 19 cm is 722 sq.cm.

We are supposed to find the area of a rectangle.

The breadth of the rectangle is half the length and the breadth is given to be 19 cm.

Let's proceed with the solution to find the length of the rectangle.

First, we need to find the length of the rectangle.

We know that the breadth of the rectangle is half the length.

Let's assume the length of the rectangle to be x

Then, the breadth of the rectangle = 1/2 * x = x/2

We know that the breadth of the rectangle is given to be 19 cm.

x/2 = 19

Multiplying both sides by 2,

we get x = 38 cm

Now, we know that the length of the rectangle is 38 cm and the breadth of the rectangle is 19 cm.

We can now find the area of the rectangle using the formula of the area of a rectangle.

Area of a rectangle = length * breadth= 38 * 19= 722 sq.cm

Hence, the area of the rectangle is 722 sq.cm.

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