At a certain school, 8/9 of the students are boys. Today, 2/5 of the boys brought their lunch. What fraction of the students are
boys who brought their lunch today?

Answer:

(a)

Step-by-step explanation:

Given

See attachment for sets A and B

Required

The true statement about both sets

First, we calculate the typical values (mean) of set A and set B.

This is calculated as:

[tex]Mean = \frac{\sum fx}{\sum f}[/tex]

For A:

[tex]A= \frac{0*1+2*1+5*1+6*1+7*1}{1+1+1+1+1}[/tex]

[tex]A= \frac{20}{5}[/tex]

[tex]A =4[/tex]

For B:

[tex]B = \frac{7 * 1 + 8 *1 + 9 * 2 + 10 * 1}{1+1+2+1}[/tex]

[tex]B = \frac{43}{5}[/tex]

[tex]B = 8.6[/tex]

Here, we can conclude that B has a larger typical value

Next calculate the spread (range) of sets A and B

This is calculated as:

[tex]Range = Highest -Least[/tex]

For A:

[tex]A = 7 - 0[/tex]

[tex]A = 7[/tex]

For B

[tex]B=10 - 7[/tex]

[tex]B = 3[/tex]

Here, we can conclude that A has a larger spread.

Hence, (a) is true

If Sº f(a)dz f(x)dx = 35 35 and o [*p12 g(x)dx = 12, find [3f(x) + 59(2)]da. The value of indefinite integral [3f(x) + 59(2)]da If Sº f(a)dz f(x)dx = 35 35 and o [*p12 g(x)dx = 12 is 223.

We are given the following conditions:

Sº f(a)dz f(x)dx = 35

35o [*p12 g(x)dx = 12

First, we need to evaluate the indefinite integral.

Hence, integrating (x² + x + 17)34c + x² with respect to x, we get,

x³/3 + 17x² + 34cx + x³/3 + C= (2/3) x³ + 17x² + 34cx + C

To find [3f(x) + 59(2)]da,

we need to integrate the same with respect to a.

[3f(x) + 59(2)]da= 3Sº

f(x)da + 59(2)a= 3Sº f(a)dz f(x)dx + 118

Therefore,[3f(x) + 59(2)]da= 3 × 35 + 118= 223

Therefore, [3f(x) + 59(2)]da= 223.

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Answer:

your answer is 1/2 hope this helped have a good day :3

Step-by-step explanation:

Answer:

1/2 or 0.5

Step-by-step explanation:

5/3 + (- 7/6)​ = 5/3 - 7/6

Using Euler's method we get:

y_1 = 1

using the analytical solution:

y = 1.225

We can estimate the accuracy of the result of the first calculation to be approximately `0.0003927`.

Let's begin by solving the given differential equation using Euler's method.

Using Euler's method we can estimate the value of `y` at a point using the following equation:

y_n+1 = y_n + h*f(x_n,y_n), where h is the step size given by

`h=x_(n+1)-x_n`.

Given that `dy/dx = x/y` we have that `y dy = x dx`. Integrating both sides we get:

(1/2)y^2 = (1/2)x^2 + C where C is the constant of integration.

To find `C` we use the initial condition `y(0)=1`.

This gives:

(1/2)(1)^2 = (1/2)(0)^2 + C => C = 1/2

Therefore the solution is given by: y^2 = x^2 + 1/2 => y = sqrt(x^2 + 1/2)

Now to estimate `y(1)` using the Euler's method, we have:

x_0 = 0, y_0 = 1, h = 0.1

Using Euler's method we get:

y_1 = y_0 + h*(x_0/y_0) = 1 + 0.1*(0/1) = 1

Now, we will improve the result using h= 0.05 and compare both results with the analytical solution.

x_0 = 0, y_0 = 1, h = 0.05

Using Euler's method we get:

y_1 = y_0 + h*(x_0/y_0) = 1 + 0.05*(0/1) = 1

Now, using the analytical solution:

y = sqrt(x^2 + 1/2) => y(1) = sqrt(1 + 1/2) = sqrt(3/2) = 1.225

Using Euler's method we get y(1) = 1.0 (with h = 0.1) and 1.0 (with h = 0.05). As we can see the result is not accurate. To improve the result we can use a more accurate method like the Runge-Kutta method.

Next, we will use the predictor-corrector method to solve the given differential equation.

dy/dx = x^2+y^2 ; y(0)=0

with h = 0.01

To use the predictor-corrector method we need to first use a predictor method to estimate the value of `y` at `x_(n+1)`. For that we can use the Euler's method. Then, using the estimate, we correct the result using a better approximation method like the Runge-Kutta method.

The Euler's method gives:

y_n+1(predicted) = y_n + h*f(x_n,y_n) = y_n + h*(x_n^2 + y_n^2)y_1(predicted)

= y_0 + h*(x_0^2 + y_0^2) = 0 + 0.01*(0^2 + 0^2) = 0

Next, we will correct this result using the Runge-Kutta method of order 4.

The Runge-Kutta method of order 4 is given by: y_n+1 = y_n + (1/6)*(k1 + 2*k2 + 2*k3 + k4)

where k1 = h*f(x_n,y_n)

k2 = h*f(x_n + h/2, y_n + k1/2)

k3 = h*f(x_n + h/2, y_n + k2/2)

k4 = h*f(x_n + h, y_n + k3)

Using the given differential equation: f(x,y) = x^2 + y^2y_1 = y_0 + (1/6)*(k1 + 2*k2 + 2*k3 + k4)

where k1 = h*f(x_0,y_0) = 0

k2 = h*f(x_0 + h/2, y_0 + k1/2) = h*f(0.005, 0) = 0.000025

k3 = h*f(x_0 + h/2, y_0 + k2/2) = h*f(0.005, 0.0000125) = 0.000025

k4 = h*f(x_0 + h, y_0 + k3) = h*f(0.01, 0.0000125) = 0.000100y_1 = 0 + (1/6)*(0 + 2*0.000025 + 2*0.000025 + 0.000100) = 0.0000583

Now, we will repeat this process for `h=0.05`.

h = 0.05

The Euler's method gives:

y_1(predicted) = y_0 + h*(x_0^2 + y_0^2) = 0 + 0.05*(0^2 + 0^2) = 0

The Runge-Kutta method of order 4 gives:

y_1 = y_0 + (1/6)*(k1 + 2*k2 + 2*k3 + k4)

where k1 = h*f(x_0,y_0) = 0

k2 = h*f(x_0 + h/2, y_0 + k1/2) = h*f(0.025, 0) = 0.000313

k3 = h*f(x_0 + h/2, y_0 + k2/2) = h*f(0.025, 0.000156) = 0.000312

k4 = h*f(x_0 + h, y_0 + k3) = h*f(0.05, 0.000156) = 0.001242y_1 = 0 + (1/6)*(0 + 2*0.000313 + 2*0.000312 + 0.001242) = 0.000451

The estimate of the accuracy of the result of the first calculation is given by the difference between the two results obtained using `h=0.01` and `h=0.05`. This is:

y_1(h=0.05) - y_1(h=0.01) = 0.000451 - 0.0000583 = 0.0003927

Therefore, we can estimate the accuracy of the result of the first calculation to be approximately `0.0003927`.

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The phrases used to describe an upper-tail test are "is greater than," "is bigger than," "is above," and "is not equal to." and the phrases used to describe a two-tail test are "is not the same as," "is different from," and "is not equal to."

a) The hypothesis testing process is based on the assumption that the null hypothesis is true, which means that there is no significant difference between the observed and expected data. The alternative hypothesis is a statement that contradicts the null hypothesis and suggests that the observed data is different from the expected data. A hypothesis test involves testing the null hypothesis against the alternative hypothesis using a test statistic and a significance level. The significance level is the probability of rejecting the null hypothesis when it is true. If the p-value is less than the significance level, then we reject the null hypothesis and accept the alternative hypothesis. Otherwise, we fail to reject the null hypothesis.

b) The phrases used to describe an upper-tail test are "is greater than," "is bigger than," "is above," and "is not equal to." An upper-tail test is a one-tailed test that is used to determine if the sample mean is significantly greater than the population mean. The null hypothesis for an upper-tail test is that the population mean is less than or equal to the sample mean. The alternative hypothesis is that the population mean is greater than the sample mean.

c) The phrases used to describe a two-tail test are "is not the same as," "is different from," and "is not equal to." A two-tail test is used to determine if the sample mean is significantly different from the population mean. The null hypothesis for a two-tail test is that the population mean is equal to the sample mean. The alternative hypothesis is that the population mean is not equal to the sample mean.

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Answer:

Step-by-step explanation:

Answer:

its 3, -6,-1... got 100%

Step-by-step explanation:

Answer: It would be "290 in.2"

Step-by-step explanation:

a) The derivative of a constant times a constant is zero, so the derivative of da ([8] c*) with respect to c* is zero. b) there is no value of k that satisfies this equation. c) k = 2/e

a. The derivative of a constant times a constant is zero, so the derivative of da ([8] c*) with respect to c* is zero.

b. To find a value of k such that ekt is a solution to a = -4, we substitute ekt into the equation:

a = -4

ekt = -4

Since ekt is always positive, there is no value of k that satisfies this equation.

c. To find a value of k such that ekt is a solution to ' = 2, we substitute ekt into the equation:

' = 2

d(ekt)/dt = 2

Differentiating ekt with respect to t, we get:

kekt = 2

Dividing both sides by ek, we have:

k = 2/e

d. The general solution for the system of differential equations in the form x₁(t) = ? and x₂(t) = ? can be obtained by solving the system using the initial conditions and finding the values of the arbitrary constants A and B.

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Answer:

Try 8 if it's wrong sorry

Step-by-step explanation:

Answer:

12 cm difference

Step-by-step explanation:

√64 cm² = 8 cm

8 cm x 4 = 32 cm perimeter

√121 cm² = 11 cm

11 cm x 4 = 44 cm perimeter

44 cm - 32 cm = 12 cm difference

The 90% confidence level means that we are 90% confident that the true median household income for Arizona falls within the given interval.

In statistical analysis, a confidence interval provides a range of values within which the true population parameter is likely to lie. In this case, the 90% confidence interval for the 2015 median household income in Arizona is stated as $51,492 ± $431.

Interpreting this confidence interval, we can say that we are 90% confident that the true median household income for Arizona in 2015 falls between $51,061 ($51,492 - $431) and $51,923 ($51,492 + $431). This means that if we were to take multiple samples and calculate their respective confidence intervals, approximately 90% of these intervals would contain the true median household income.

The confidence level represents the degree of certainty associated with the interval. In this case, a confidence level of 90% means that there is a 90% probability that the true median household income lies within the given range. It indicates a high level of confidence but allows for a 10% chance of the true value falling outside the interval.

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To find the area using the limit of a sum (a Riemann sum) of the region between the graph of y = f(x) and the x-axis from x = a to x = b, the formula is given by: Area = lim n → ∞ ∑ i = 1 n f(x* i )Δx, where f(x* i ) is the height of the ith rectangle and Δx is the width of the ith rectangle.

To find the area between the graph of y = f(x) and the x-axis from x = a to x = b using the limit of a sum, we need to first divide the interval [a, b] into n equal subintervals of length Δx = (b - a)/n. Then, we can choose any point x* i in the ith subinterval [x i-1 , x i ] and use it to determine the height of the ith rectangle f(x* i ).

Finally, we can take the limit as n approaches infinity to obtain the exact area of the region between the graph of y = f(x) and the x-axis from x = a to x = b.

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To sketch an approximate solution curve passing through specific points, integrate the differential equation numerically Euler's method, Runge-Kutta methods, or solve the equation analytically if possible

To generate a direction field for a given differential equation using computer software, you can use mathematical software packages such as MATLAB, Python with libraries like NumPy and Matplotlib, or dedicated software like Wolfram Mathematica. Here, I will explain the general procedure using Python and Matplotlib.

Define the differential equation: Write down the differential equation you want to work with. For example, let's say we have a first-order ordinary differential equation dy/dx = x - y.

Import the necessary libraries: In Python, you'll need to import the required libraries, such as NumPy and Matplotlib. You can do this with the following code:

python

Copy code

import numpy as np

import matplotlib.pyplot as plt

Define the direction field function: Create a Python function that calculates the slope at each point (x, y) based on the given differential equation. For our example equation dy/dx = x - y, the function can be defined as follows:

python

Copy code

def direction_field(x, y):

   return x - y

Generate a grid of points: Define the range of x and y values over which you want to generate the direction field. Create a mesh grid using NumPy's meshgrid function to generate a grid of points (x, y). For example:

python

Copy code

x = np.linspace(-5, 5, 20)

y = np.linspace(-5, 5, 20)

X, Y = np.meshgrid(x, y)

Calculate the slopes: Use the direction_field function to calculate the slopes (dy/dx) at each point in the grid. Store the result in a variable, such as dy_dx:

python

Copy code

dy_dx = direction_field(X, Y)

Plot the direction field: Use Matplotlib's quiver function to plot the direction field. This function creates arrows at each point (x, y) in the grid, indicating the direction of the slope (dy/dx). Here's an example:

python

Copy code

plt.figure(figsize=(8, 8))

plt.quiver(X, Y, np.ones_like(dy_dx), dy_dx)

plt.xlabel('x')

plt.ylabel('y')

plt.title('Direction Field')

plt.grid(True)

plt.show()

This code will display the direction field for the given differential equation.

To sketch an approximate solution curve passing through specific points, you can integrate the differential equation numerically using numerical integration methods such as Euler's method, Runge-Kutta methods, or solve the equation analytically if possible. Once you have the solution, you can plot it on top of the direction field using Matplotlib to compare it with the given points.

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Answer:

$6.41

Step-by-step explanation:

47.92 - 3.05 = 44.87

44.87/7 = $6.41

Answer:

-4

Step-by-step explanation:

First you add together 75 + 65 to get 140 then you subtract that from 180 because 180° is the total of a triangle. Then you add -4 to 44 to get 40

Answer:

-4

Step-by-step explanation:

75 + 65 = 140

triangle angels equal 180°

then x +44 = 180-140

x +44 = 40

x = 40-44

x = -4

Answer:

8

Step-by-step explanation:

18. Option B is correct, the outcomes of the first five spins tell us nothing about what will happen on the next five spins.

19. Option D is correct,  the overall sample is a simple random sample, biased due to imbalance and stratified sample, option d is correct.

18. Given that a  North American roulette wheel has 38 slots, of which 18 are red, 18 are black, and 2 are green.

Each spin of the roulette wheel is an independent event, and the outcomes of previous spins do not influence the outcomes of future spins.

The wheel has no memory of previous results, so the probability of getting a red outcome on the sixth spin is the same as any other spin – 18 out of 38.

So, the outcomes of the first five spins tell us nothing about what will happen on the next five spins.

19. At a large university, a simple random sample of five female professors is selected, and a simple random sample of 10 male professors is selected.

The overall sample of 15 professors is a combination of two simple random samples, one from the female professors and the other from the male professors.

This makes it a stratified sample because it involves dividing the population (professors) into distinct groups (male and female) and then randomly sampling from each group.

Additionally, the overall sample can also be considered a simple random sample because it was obtained by randomly selecting individuals from the population without any bias

Hence, the overall sample is a simple random sample, biased due to imbalance and stratified sample, option d is correct.

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Answer:

Step-by-step explanation:

An absolute value of |x| {modulus of x} is the value of a real number x. The given equation is not true.

An absolute value of |x| {modulus of x} is the value of a real number x, the value we get is always a non-negative number, for example, |-5| will give 5, and also, |5| will give 5 as well.

A hypothesis is a speculative conclusion or assertion that is made without proof. Now, to prove that the given equation is not true substitute the value of both the variables as -1. Therefore,

x = y = -1

Substitute the value on the left side of the equation,

|x - y|

= |-1 - (-1)|

= |-1 + 1|

= |0|

= 0

Substitute the value on the right side of the equation,

|x| - |y|

= |-1| - |-1|

= 1 + 1  

= 2

Since the left and the right side of the equation is not satisfied, therefore, it can be concluded that the given equation is not true.

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According to the question You have two coins, a blue and a red one. You choose one of the coins at random, each being chosen with probability are as follows :

(a) To compute P(H1), we need to consider the probability of getting heads on the first toss. There are two scenarios: either we picked the blue coin and got heads, or we picked the red coin and got heads.

[tex]\(P(H1) = P(H1 \cap B) + P(H1 \cap \bar{B}) = P(H1 | B)P(B) + P(H1 | \bar{B})P(\bar{B}) = 0.8 \times \frac{1}{2} + 0.2 \times \frac{1}{2} = 0.4 + 0.1 = 0.5\)[/tex]

(b) To compute P(H2), we can use the same reasoning as in part (a), considering the probability of getting heads on the second toss.

[tex]\(P(H2) = P(H2 \cap B) + P(H2 \cap \bar{B}) = P(H2 | B)P(B) + P(H2 | \bar{B})P(\bar{B}) = 0.8 \times \frac{1}{2} + 0.2 \times \frac{1}{2} = 0.4 + 0.1 = 0.5\)[/tex]

(c) To compute P(H1 ∩ B), we consider the probability of getting heads on the first toss given that we picked the blue coin.

[tex]\(P(H1 \cap B) = 0.8 \times \frac{1}{2} = 0.4\)[/tex]

(d) To compute P(H1 ∩ H2), we need to consider the probability of getting heads on both the first and second toss.

[tex]\(P(H1 \cap H2) = P(H1)P(H2 | H1)\)[/tex]

(e) The independence of events H1 and H2 can be determined by comparing [tex]\(P(H2 | H1)\)[/tex]  and [tex]\(P(H2)\)[/tex] .

(f) To compute P(H2 | H1), we use the formula for conditional probability:

[tex]\(P(H2 | H1) = \frac{P(H1 \cap H2)}{P(H1)} = \frac{0.4}{0.5} = 0.8\)[/tex]

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Answer:

Option B

Step-by-step explanation:

→ Find 2 coordinates through which the line passes through

( -2 , -5 ) and ( 0 , -1 )

→ Work out the gradient

[tex]\frac{-1--5}{0--2} =2[/tex]

→ Write into y = mx + c

y = 2x + c

→ Substitute in the coordinates ( 0 , -1 )

-1 = 0 + c so c = -1

→ Write equation

y = 2x - 1

→ Expand out all the equations and simply to see which gives y = 2x - 1

Option B

The system has infinitely many solutions.

The given augmented matrix represents a system of linear equations. To find the reduced row-echelon form, we perform row operations to transform the matrix into a triangular form with leading entries (1s) and zeros below each leading entry. Let's denote the variables as x, y, and z.

After performing the necessary row operations, we arrive at the reduced row-echelon form:

From the reduced row-echelon form, we can deduce the following equations:

These equations reveal that the system contains infinitely many solutions. By assigning a parameter, such as z = t, where t represents any real number, we can express the solutions in terms of the parameter. Thus, the coordinates of the solution are given by:

In this case, there is an infinite number of possible solutions, and each solution is represented by a unique value of t. Therefore, the main answer is that the system has infinitely many solutions.

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Answer:

bit.[tex]^{}[/tex]ly/3a8Nt8n

Step-by-step explanation:

Answer:

804 cm3

Step-by-step explanation:

multiply the lenght and the width then multiply by 3.14 which is pi.

Answer:

scale factor = 20%

Step-by-step explanation:

A scale factor is a multiplier which can be used to determine the rate between two or more dimensions.

In the given figure, the sides of the original triangle is 5 times greater than that of the copy. Thus,

the scale factor = [tex]\frac{copy length}{original length}[/tex] x 100%

                          = [tex]\frac{1}{5}[/tex] x 100%

                          = 20%

The scale factor of the original triangle to its copy is 20%. This implies that the dimensions of the original triangle are multiplied by 20% to determine that of the corresponding copy triangle. Thus, we scale down the dimensions of the original triangle by 20%.

Answer:

Step-by-step explanation:

Answer:

I don't see an "x" or an equation-

Answer:

234

Step-by-step explanation:

Answer:

234

Step-by-step explanation:

AREA FOR TRIANGLE: bh/2

b = base

h = height

-

30 x 15.6 = 468

468/2 = 234

-

hope this helped ! :D

a. The function in graph q is classified as an odd function, as f(-x) = -f(x).

b. The function in graph q is classified as an even function, as f(-x) = f(x).

c. The function [tex]y = 3^x - 4[/tex] is classified as neither an odd function nor an even function.

For the third function, [tex]y = 3^x - 4[/tex], we have that:

No relation between f(1) and f(-1), hence the function is neither even nor odd.

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Step-by-step explanation:

Let's find the difference between 7508 and the other numbers.

A. 5706 - 7508 = -1802

B. 6993 - 7508 = -515

C. 8108 - 7508 = 600

D. 8522 - 7508 = 1014

E. 1050 - 7508 = -6458

If we do not take +ve / -ve into account,

the closest number to 7508 = the smallest difference

which in this case, is B, 6993.

Answer:

B. 6993

Step-by-step explanation:

hope this helps :)