Solve 5x - 10y = -40 for y

When is the net force on an object equal to zero?

morpeh [17]

I believe it is when the forces action on the object are balanced. Hope it helps!

7 0

3 years ago

According to the National Institute on Drug Abuse, a U.S. government agency, 17.3% of 8th graders in 2010 had used marijuana at

miskamm [114]

Answer:

The conditions for use of the normal model to represent the distribution of sample proportion are not met. He should increase the sample size until the conditions are met.

If the test is done anyway, the null hypothesis failed to be rejected.

The conclusion is taht there is not enough evidence to support the claim that the percentage is lower in this district.

Step-by-step explanation:

The conditions for use of the normal model to represent the distribution of sample proportion are not met, as the affirmative responses are less than 10.

$np=80*0.1=8$

If the test of hypothesis is done as if the conditiones were met, we know that the claim is that the percentage is lower in this district.

Then, the null and alternative hypothesis are:

$H_0: \pi=0.173\\\\H_a:\pi$

The significance level is 0.05.

The sample has a size n=80.

The sample proportion is p=0.1.

The standard error of the proportion is:

$\sigma_p=\sqrt{\dfrac{\pi(1-\pi)}{n}}=\sqrt{\dfrac{0.173*0.827}{80}}\\\\\\ \sigma_p=\sqrt{0.001788}=0.042$

Then, we can calculate the z-statistic as:

$z=\dfrac{p-\pi+0.5/n}{\sigma_p}=\dfrac{0.1-0.173+0.5/80}{0.042}=\dfrac{-0.067}{0.042}=-1.578$

This test is a left-tailed test, so the P-value for this test is calculated as:

$P-value=P(z$

As the P-value (0.057) is greater than the significance level (0.05), the effect is not significant.

The null hypothesis failed to be rejected.

There is not enough evidence to support the claim that the percentage is lower in this district.

7 0

3 years ago

To calculate the cost of painting his silo, a farmer must find its height. The farmer uses a cardboard square to line up the top

tankabanditka [31]

Answer:

Height of the silo = 18 feet.

Step-by-step explanation:

From the figure attached BC is the length of the silo and the height of the farmer is 5 ft.

Farmer is standing at 8 ft distance from the silo.

From triangle AEC,

tan(∠CAE) = $\frac{CE}{AE}$

= $\frac{5}{8}$

m(∠CAE) = $tan^{-1}(\frac{5}{8})$

= 32°

m∠BAE = 90° - 32° = 58°

From the triangle ABE,

tan58° = $\frac{BE}{AE}$

BE = 8tan58°

BE = 12.8 ft

Total height of the silo = BE + EC

= 12.8 + 5

= 17.8

≈ 18 ft

Therefore, total height of the silo is 18 ft.

3 0

3 years ago

A boat travels 45 miles east (right) then 60 miles north (up), how far is it from the starting point?

tekilochka [14]

A boat travels 45 miles east then 60 miles north, how far is it from where it started. Draw this. The hypotenuse of the right triangle is the square root (45^2)+(60^2)=square root of 2025=3600=square root of 5625, or 75 miles.

7 0

3 years ago

Read 2 more answers

Two boys and three girls are auditioning to play the piano for a school production. Two students will be chosen, one as the pian

finlep [7]

Answer:

30% is the correct answer.

Step-by-step explanation:

Total number of boys = 2

Total number of girls = 3

Total number of students = 5

To find:

Probability that the pianist will be a boy and the alternate will be a girl?

Solution:

Here we have to make 2 choices.

1st choice has to be boy (pianist) and 2nd choice has to be girl (alternate).

$\bold{\text{Required probability }= P(\text{boy as pianist first}) \times P(\text{girl as alternate})}$

Formula for probability of an event E is given as:

$P(E) = \dfrac{\text{Number of favorable cases}}{\text {Total number of cases}}$

For $P(\text{boy as pianist})$ , number of favorable cases are 2 (total number of boys).

Total number of cases = Total number of students i.e. 5

So, $P(\text{boy as pianist})$ is:

$P(\text{boy as pianist}) = \dfrac{2}{5}$

For $P(\text{girl as alternate})$ , number of favorable cases are 3 (total number of girls).

Now, one boy is already chosen as pianist so Total number of cases = Total number of students left i.e. (5 - 1) = 4

$P(\text{girl as alternate}) = \dfrac{3}{4}$

So, the required probability is:

$\text{Required probability } = \dfrac{2}{5}\times \dfrac{3}{4} = \dfrac{3}{10} = \bold{30\%}$

6 0

3 years ago