Which of the following is the best example of a statistical question?

A fair die os flipped 6 times. What is the probability of rolling at least one 3? Round the answer to the nearest hundredth of a

Yuliya22 [10]

Answer:

it would be 18

Step-by-step explanation:

5 0

3 years ago

A small rocket is fired from a launch pad 10 m above the ground with an initial velocity left angle 250 comma 450 comma 500 righ

jonny [76]

Let $\vec r(t),\vec v(t),\vec a(t)$ denote the rocket's position, velocity, and acceleration vectors at time $t$ .

We're given its initial position

$\vec r(0)=\langle0,0,10\rangle\,\mathrm m$

and velocity

$\vec v(0)=\langle250,450,500\rangle\dfrac{\rm m}{\rm s}$

Immediately after launch, the rocket is subject to gravity, so its acceleration is

$\vec a(t)=\langle0,2.5,-g\rangle\dfrac{\rm m}{\mathrm s^2}$

where $g=9.8\frac{\rm m}{\mathrm s^2}$ .

a. We can obtain the velocity and position vectors by respectively integrating the acceleration and velocity functions. By the fundamental theorem of calculus,

$\vec v(t)=\left(\vec v(0)+\displaystyle\int_0^t\vec a(u)\,\mathrm du\right)\dfrac{\rm m}{\rm s}$

$\vec v(t)=\left(\langle250,450,500\rangle+\langle0,2.5u,-gu\rangle\bigg|_0^t\right)\dfrac{\rm m}{\rm s}$

(the integral of 0 is a constant, but it ultimately doesn't matter in this case)

$\boxed{\vec v(t)=\langle250,450+2.5t,500-gt\rangle\dfrac{\rm m}{\rm s}}$

and

$\vec r(t)=\left(\vec r(0)+\displaystyle\int_0^t\vec v(u)\,\mathrm du\right)\,\rm m$

$\vec r(t)=\left(\langle0,0,10\rangle+\left\langle250u,450u+1.25u^2,500u-\dfrac g2u^2\right\rangle\bigg|_0^t\right)\,\rm m$

$\boxed{\vec r(t)=\left\langle250t,450t+1.25t^2,10+500t-\dfrac g2t^2\right\rangle\,\rm m}$

b. The rocket stays in the air for as long as it takes until $z=0$ , where $z$ is the $z$ -component of the position vector.

$10+500t-\dfrac g2t^2=0\implies t\approx102\,\rm s$

The range of the rocket is the distance between the rocket's final position and the origin (0, 0, 0):

$\boxed{\|\vec r(102\,\mathrm s)\|\approx64,233\,\rm m}$

c. The rocket reaches its maximum height when its vertical velocity (the $z$ -component) is 0, at which point we have

$-\left(500\dfrac{\rm m}{\rm s}\right)^2=-2g(z_{\rm max}-10\,\mathrm m)$

$\implies\boxed{z_{\rm max}=125,010\,\rm m}$

7 0

3 years ago

In a certain town, 22% of voters favor a given ballot measure. For groups of 21 voters, find the variance for the number who fav

raketka [301]

c. 4.6

21 X .22= 4.6

Calculating the variance requires finding the product of 21 and 22%. To make this easier we convert 22% into it's decimal form and construct the equation. To back check this answer we can use 10% of 21 voters which equals 2.1% then double that amount to reach 4.2%, knowing that we now have a close approximation of the variance we can eliminate answers a, b, and d, leaving c as the only logical choice.

4 0

3 years ago

Terrence opens a savings account with a deposit of $1000. After 1 year he receives $50 in interest. What is the annual interest

geniusboy [140]

Answer:

Step-by-step explanation:

So, I'm pretty sure this is a problem about compound interest.

The formula for compound interest is A = p(1 + r/n)^nt

For this problem, $1000 is p, the initial amount; A is the total amount, or $1050.

What the problem is asking for is r, the interest rate, which is divided by n. N is the number of times the interest rate is compounded per year; Since the question is asking for the annual interest rate, N would be equal to 1. And because Terrence is has only left his money in for a year, t would also be equal to one.

So, by filling in the formula some, we get this:

$1050 = $1000(1 + r/1)^1*1

To find r, we would need to isolate it in the problem.

1. First, distribute $1000 to the parenthesis(keep in mind that 1000, is also equal to 1000/1:

1050 = (1000 + 1000r/1)^1

2. Then subtract 1000 from both sides:

50 = (1000r/1)^1

3. Multiple both sides by one:

50 = (1000r)^1

4. Divide both sides by 1000:

.05 = r^1 or .05 = r.

The answer is A, 5%.

8 0

4 years ago

Please help. I’ll mark you as brainliest if correct!

OLEGan [10]

Answer:

x +0y+0z = 400

-x +y+0z = 150

-8x +0y +z = 250

Step-by-step explanation:

The last column is the solution

The rest of the columns are the coefficients of the variables

x +0y+0z = 400

-x +y+0z = 150

-8x +0y +z = 250

5 0

3 years ago