Ask question

Ask question

All categories

2 years ago

15

Une échelle est posée contre un mur et une caisse cubique de 1m de côté La distance entre le bas de l'échelle et la caisse est d

e 1.40 M calculer si possible la distance entre le haut de l'échelle et le sol

1 answer:

kogti [31]2 years ago

4 0

I am not a French student

You might be interested in

A researcher wishes to estimate the percentage of adults who support abolishing the penny. What size sample should be obtained i

Scorpion4ik [409]

Answer:

a) We need a sample size of at least 3109.

b) We need a sample size of at least 4145.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

99% confidence level

So $\alpha = 0.01$ , z is the value of Z that has a pvalue of $1 - \frac{0.01}{2} = 0.995$ , so $Z = 2.575$ .

(a) he uses a previous estimate of 25%?

we need a sample of size at least n.

n is found when $M = 0.02, \pi = 0.25$ . So

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.02 = 2.575\sqrt{\frac{0.25*0.75}{n}}$

$0.02\sqrt{n} = 2.575\sqrt{0.25*0.75}$

$\sqrt{n} = \frac{2.575\sqrt{0.25*0.75}}{0.02}$

$(\sqrt{n})^{2} = (\frac{2.575\sqrt{0.25*0.75}}{0.02})^{2}$

$n = 3108.1$

We need a sample size of at least 3109.

(b) he does not use any prior estimates?

When we do not use any prior estimate, we use $\pi = 0.5$

So

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.02 = 2.575\sqrt{\frac{0.5*0.5}{n}}$

$0.02\sqrt{n} = 2.575\sqrt{0.5*0.5}$

$\sqrt{n} = \frac{2.575\sqrt{0.5*0.5}}{0.02}$

$(\sqrt{n})^{2} = (\frac{2.575\sqrt{0.5*0.5}}{0.02})^{2}$

$n = 4144.1$

Rounding up

We need a sample size of at least 4145.

8 0

3 years ago

a vegetarian sandwich is in the aproximate shape of a cone. the height of the sandwich is 6 inches and the base diameter is 3.5

Olenka [21]

Answer: 19.2inches³

Step-by-step explanation:

The volume of a cone is calculated as:

= 1/3πr²h

where,

π = 3.14

r = radius = diameter/2 = 3.5/2 = 1.75

h = height = 6

Volume = 1/3πr²h

= 1/3 × 3.14 × 1.75² × 6

= 19.2325

= 19.2inches³

Therefore, the volume of the cone-shaped sandwich is 19.2inches³.

5 0

2 years ago

Tanya is buying a skateboard for $42.38,a helmet for $17.60,and a set of elbows an nee pads for $12.89.She estimates the total c

Mila [183]

Her estimate is lower than her actual cost because her total is 72.87 she is off by 1.72 because she only added 42,17,and 12 and forgot all about adding the cent or the .60,.38,and the .89.

4 0

2 years ago

Pedro le dice a María si cambias los billetes de 10 € que tienes por billetes de 5 € y los billetes de 5 € por billetes de 10 €

Bad White [126]

Answer: Maria has 10 bills of 5€ and 10 bills of 10€.

She has a total of 150€.

Step-by-step explanation:

Let be "f" the number of 5€ bills that Maria has and "t" the number of 10€ bills that Maria has.

Set up a system of equations:

$\left \{ {{f+t=20} \atop {5f+10t=10f+5t}} \right.$

Use the Substitution method to solve the system of equations:

1. Solve for "f" from the first equation:

$f=20-t$

2. Substitute the equation obtained into the second equation and solve for "t".

Then:

$5(20-t)+10t=10(20-t)+5t\\\\100-5t+10t=200-10t+5t\\\\20t-10t=100\\\\t=\frac{100}{10}\\\\t=10$

3. Substitute the value of "t" into the equation $f=20-t$ and evaluate:

$f=20-10\\\\f=10$

Therefore, Maria has 10 bills of 5€ and 10 bills of 10 €.

So the total amount of money she has, is:

$Total=10(5)+10(10)=150$

She has a total of 150€.

5 0

3 years ago

For the function f(x) = x + 7, what is the ordered pair for the point on the graph when x = 2b. A. ( 2b, 2b+7). B. ( 2b, x + 7).

Fynjy0 [20]

$f(2b)=2b+7\\\\
(2b,2b+7)$

6 0

3 years ago

Read 2 more answers