Plz help ASAP problem down below

Answer:

3.15 seconds is the answer.

Explanation

when the ball touches the ground, h =0

hence,

0=255-21t-16t²

16t²+21t-225=0

here a=16 ,b=21, c= -225

[tex]t= \frac{ - b± \sqrt{ {b }^{2} - 4ac} }{2a} \\ \\ t= \frac{ - 21± \sqrt{ {21}^{2} - 4 \times 16 \times - 225} }{2 \times 16} \\ = \frac{ - 21 ± \sqrt{441 - ( - 14400)} }{32} \\ = \frac{ - 21± \sqrt{14841} }{32} \\ = \frac{ - 21±121.82}{32} \\ \\ t = \frac{ - 21 + 121.82}{32} \: or \: \: t = \frac{ - 21 - 121.82}{32} \\ t = 3.15 \: \: or \: \: t = - 4.46[/tex]

time cannot be negative, hence t = -4.46 can be avoided

The ball takes 3.15 seconds to hit the ground.

Answer:

14 to 132

Step-by-step explanation:

We are given that there are 132 boys and 14 adults. Since the question is only asking for the ratio of adults to boys, we don't have to worry about the number of girls in this question. From here, we see that the question is asking for the ratio of adults to boys, so we put it in that exact order. Our answer is 14 to 132. I hope this helps and please don't hesitate to reach out with more questions!

Answer:

15.000 is cost so relate it with 265..hope it is help u.

9514 1404 393

Answer:

  D.  f^-1(x) = 3 -7x

Step-by-step explanation:

Solve x = f(y) for y to find the inverse function.

  x = f(y)

  x = (3 -y)/7 . . . . . . use the function definition

  7x = 3 -y . . . . . . . .multiply by 7

  y = 3 -7x . . . . . . . add y-7x to both sides

Then the inverse function is ...

  [tex]\boxed{f^{-1}(x)=3-7x}[/tex]

Answer:

Kindly check the attached picture

Step-by-step explanation:

The solution to the problem has been explicitly solved in the picture attached below :

We need to find a number that makes the denominator a perfect cube in other to simplify the expression which is 25/25.

Kindly check the attached picture for detailed explanation

Answer:

is it four I am not quite sure

Answer:

[tex]P(X = 0) = 0.03125[/tex]

[tex]P(X = 1) = 0.15625[/tex]

[tex]P(X = 2) = 0.3125[/tex]

[tex]P(X = 3) = 0.3125[/tex]

[tex]P(X = 4) = 0.15625[/tex]

[tex]P(X = 5) = 0.03125[/tex]

Step-by-step explanation:

For each toss, there are only two possible outcomes. Either it is tails, or it is not. The probability of a toss resulting in tails is independent of any other toss, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

Fair coin:

Equally as likely to be heads or tails, so [tex]p = 0.5[/tex]

5 tosses:

This means that [tex]n = 5[/tex]

Probability distribution:

Probability of each outcome, so:

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{5,0}.(0.5)^{0}.(0.5)^{5} = 0.03125[/tex]

[tex]P(X = 1) = C_{5,1}.(0.5)^{1}.(0.5)^{4} = 0.15625[/tex]

[tex]P(X = 2) = C_{5,2}.(0.5)^{2}.(0.5)^{3} = 0.3125[/tex]

[tex]P(X = 3) = C_{5,3}.(0.5)^{3}.(0.5)^{2} = 0.3125[/tex]

[tex]P(X = 4) = C_{5,4}.(0.5)^{4}.(0.5)^{1} = 0.15625[/tex]

[tex]P(X = 5) = C_{5,5}.(0.5)^{5}.(0.5)^{0} = 0.03125[/tex]

Answer:

the answer is x = 2 or B, hope this helps

Step-by-step explanation:

Answer:

11,000

Step-by-step explanation:

Answer:

The 95% confidence interval for the population mean of such waiting times is between 19.5 and 24.5 minutes. This means that we are 95% sure that the true mean waiting time of all calls for this company is between 19.5 and 24.5 minutes.

The 99% confidence interval for the population mean of such waiting times is between 18.6 and 25.4 minutes. This means that we are 99% sure that the true mean waiting time of all calls for this company is between 18.6 and 25.4 minutes.

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 25 - 1 = 24

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 24 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 2.0639

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.0639\frac{6}{\sqrt{25}} = 2.5[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 22 - 2.5 = 19.5 minutes

The upper end of the interval is the sample mean added to M. So it is 22 + 2.5 = 24.5 minutes

The 95% confidence interval for the population mean of such waiting times is between 19.5 and 24.5 minutes. This means that we are 95% sure that the true mean waiting time of all calls for this company is between 19.5 and 24.5 minutes.

99% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 24 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.99}{2} = 0.995[/tex]. So we have T = 2.797

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.797\frac{6}{\sqrt{25}} = 3.4[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 22 - 3.4 = 18.6 minutes

The upper end of the interval is the sample mean added to M. So it is 22 + 3.4 = 25.4 minutes

The 99% confidence interval for the population mean of such waiting times is between 18.6 and 25.4 minutes. This means that we are 99% sure that the true mean waiting time of all calls for this company is between 18.6 and 25.4 minutes.

Answer:

Evaluación de expresiones y polinomios

Purplemath

"Evaluación" significa principalmente "simplificar una expresión a un solo valor numérico". A veces se le dará una expresión numérica, donde todo lo que tiene que hacer es simplificar; esa es más una cuestión de orden de operaciones. En esta lección, me concentraré en el aspecto de la evaluación de "conectar y tragar": introducir valores para las variables y "avanzar" hasta llegar a la respuesta simplificada.

(Por cierto, sí, "plug-n-chug" es una terminología bastante estándar. No es un término "técnico", por lo que probablemente no lo verá en su libro de texto, pero seguramente lo escuchará de otros estudiantes. , y quizás también su instructor.)

MathHelp.com

Evaluar expresiones en MathHelp.com

Evaluar expresiones

Por lo general, la única parte difícil de la evaluación es hacer un seguimiento de los signos "menos". Le recomiendo encarecidamente que utilice los paréntesis libremente, especialmente cuando recién está comenzando.

Evalúe a2b para a = –2, b = 3, c = –4 y d = 4.

Anuncio publicitario

Para encontrar mi respuesta, simplemente conecto los valores dados, teniendo cuidado de usar paréntesis, particularmente alrededor de los signos "menos". Especialmente cuando recién estoy comenzando, dibujar los paréntesis primero puede ser útil:

a2 b

() 2 ()

(–2) 2 (3)

(4) (3)

12

Observe cómo el uso de paréntesis me ayudó a realizar un seguimiento del signo "menos" en el valor de a. Esto era importante, porque de otro modo podría haber elevado al cuadrado solo el 2, terminando con –4, lo que habría estado mal.

Por cierto, resultó que no necesitábamos los valores de las variables c y d. Cuando se le da un gran conjunto de expresiones para evaluar, debe esperar que a menudo haya una u otra de las variables que no se incluirán en ningún ejercicio en particular del conjunto.

Evalúe a - cd para a = –2, b = 3, c = –4 y d = 4.

En este ejercicio, me dieron información adicional. No hay una b en la expresión que quieren que evalúe, por lo que puedo ignorar este valor en mi trabajo:

(–2) - (–4) (4)

–2 - (–16)

–2 + 16

16 - 2

14

Step-by-step explanation:

hola

Answer:

200 test tubes will fill the container

Step-by-step explanation:

Hi there!

We need to find out how many 5 milliliter tubes will fill a 1 liter container

First, let's convert everything to the same unit, as the tubes and the container are in different units.

Let's do milliliters, as those are smaller than liters and we will avoid having decimals.

there are 1,000 milliliters in a liter (the unit prefix "milli-" means "thousand")

Let's say the number of test tubes needed to fill the container is x

As each tube has 5 milliliters of water, 5x milliliters will equal 1,000 milliliters (1 liter)

as an equation, that's

5x=1,000

divide both sides by 5

x=200

So that means 200 test tubes will fill the container

Hope this helps! :)

Answer:

Here is how to start

Step-by-step explanation:    7  2  13  42

1 milliliter is one one thousands of a liter      1 milliliter  = 0.001 liter

1000 milliliter is equal to 1 liter

How many 5 milliliter test tubes are in 1 liter?

1000 milliliter / 5 milliliter per test tube   =  ________  test tubes

Answer:

a AND ~c

Step-by-step explanation:

you can find the full explanation in wikipedia:

https://en.m.wikipedia.org/wiki/Material_conditional

under "Negated conditionals"

Answer:

$637.50

Step-by-step explanation:

According to the Question,

Thus, the first months interest is

$200,000 list price x 0.90 = $180,000 contract sales price.

Since lender always uses the less of the appraised value or the contract sales price, use $180,00 for the remainder of the calculations.

Answer:

$637.50

Step-by-step explanation:

The appraised value is irrelevant. The lender will consider the lower of the appraised value or the agreed purchase price.

The term of the loan is also irrelevant. It is not an amortization problem.

The first month’s interest is $637.50.

9514 1404 393

Answer:

  D  neither

Step-by-step explanation:

Reflection across a vertical line is required to change the figure left-to-right without changing it top-to-bottom. Translation along a directed line segment must then map corresponding points.

Sequence A involves reflection over a horizontal line, so can be rejected immediately. Sequence B does the translation so that point N gets moved to the location of point B. However, point N corresponds to point D (see the similarity statement), so that translation is inappropriate.

Neither sequence will map KLMN to ABCD.

Answer:

0.9029 = 90.29% probability that the mean of the sample would differ from the population mean by less than 3.8 points if 76 exams are sampled

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

The mean points obtained in an aptitude examination is 167 points with a standard deviation of 20 points

This means that [tex]\mu = 167, \sigma = 20[/tex]

Sample of 76:

This means that [tex]n = 76, s = \frac{20}{\sqrt{76}}[/tex]

What is the probability that the mean of the sample would differ from the population mean by less than 3.8 points?

P-value of Z when X = 167 + 3.8 = 170.8 subtracted by the p-value of Z when X = 167 - 3.8 = 163.2. So

X = 170.8

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{170.8 - 167}{\frac{20}{\sqrt{76}}}[/tex]

[tex]Z = 1.66[/tex]

[tex]Z = 1.66[/tex] has a p-value of 0.9515

X = 163.2

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{163.2 - 167}{\frac{20}{\sqrt{76}}}[/tex]

[tex]Z = -1.66[/tex]

[tex]Z = -1.66[/tex] has a p-value of 0.0485

0.9514 - 0.0485 = 0.9029

0.9029 = 90.29% probability that the mean of the sample would differ from the population mean by less than 3.8 points if 76 exams are sampled

can you show a picture of the symbols

Answer:

[tex]d_2=-8.32ft[/tex]

Step-by-step explanation:

From the question we are told that:

Height of first draw down [tex]h=30[/tex]

Pump Discharge [tex]Q=250gallons/day[/tex]

Well 1 depth [tex]d_1=10ft[/tex]

Transmissivity[tex]\=T 10.0 ft2/day[/tex]

Radius[tex]r=0.5[/tex]

Well 2 depth [tex]d_2=50ft[/tex]

Generally the Thiem's equation for Discharge is mathematically given by

 [tex]Q=\frac{2\piT(h_2-h_1)}{ln(\frac{r_2}{r_1})}[/tex]

 [tex]250=\frac{2*\pi 10 (10-d_2)}{ln(\frac{50}{0.5})}[/tex]

 [tex]1151.293=2*\pi 10 (10-d_2)[/tex]

 [tex]d_2=-8.32ft[/tex]

Answer:

option D

Step-by-step explanation:

[tex]sin^2 ( \frac{3\pi}{2}) + cos^2(\frac{3\pi}{2}) = 1\\\\( -1)^2 + 0^2 = 1[/tex]

Explanation:

[tex]sin x = cos( \frac{\pi}{2} - x)\\\\sin(\frac{3\pi}{2}) = cos ( \frac{\pi}{2} - \frac{3\pi}{2})\\[/tex]

            [tex]=cos(\frac{\pi - 3\pi}{2})\\\\ =cos(\frac{2\pi}{2})\\\\=cos \ \pi\\\\= - 1[/tex]

Therefore ,

               [tex]sin^2( \frac{3\pi}{2}) = ( - 1)^2[/tex]

Step-by-step explanation:

ejejejejrjruruehehhr

Answer: 1. When you estimate, it is not an exact measurement. 3ft 8 in gets rounded to 4ft and 12 ft 3 in rounds to 12ft. now find the perimeter. P=2l+2w P= 2*12 +2*4 P=32feet

2. 3ft 8in = 3 8/12 or reduced to 3 2/3  12ft 3in = 12 3/12 or reduced to 12 1/4   The fractional part is referring to a fraction of a foot.

3. The perimeter of the room is P=2l+2w or P=2(12 1/4) + 2(3 2/3) p=24 1/2 + 7 1/3  P= 31 5/6 feet

4. The estimate and the actual are very close. They are 1/6 of a foot apart.

5a. Total baseboard 31 5/6ft - 2 1/4 ft = 29 7/12 feet needed.

5b. Take the total and divide it by 8ft  = 29 7/12 divided by 8= 3.7  You are not buying a fraction of a board so you would need 4 boards.

Answer:

Step-by-step explanation:

-2

Step-by-step explanation:

28:20

Once simplified its 7:5

Answer:

Let's solve for k.

x2−y2=k

Step 1: Flip the equation.

k=x2−y2

Answer:

k=x2−y2

Step-by-step explanation:

Answer:

[tex](f + g)(4) = 191[/tex]

Step-by-step explanation:

Given

[tex]f(x) = 5x^2 - 5x + 15[/tex]

[tex]g(x) = 6x^2 + 7x - 8[/tex]

Required

[tex](f + g)(4)[/tex]

First, calculate [tex](f + g)(x)[/tex]

This is calculated as:

[tex](f + g)(x) = f(x) + g(x)[/tex]

So, we have:

[tex](f + g)(x) = 5x^2 - 5x + 15+6x^2 + 7x - 8[/tex]

Collect like terms

[tex](f + g)(x) = 5x^2 +6x^2 - 5x+ 7x + 15 - 8[/tex]

[tex](f + g)(x) = 11x^2 + 2x + 7[/tex]

Substitute 4 for x

[tex](f + g)(4) = 11*4^2 + 2*4 + 7[/tex]

[tex](f + g)(4) = 191[/tex]