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3 years ago

Akash left his house and walked west 7 kilometers

Mathematics

1 answer:

Mila [183]3 years ago

5 0

is that a math question? can you type out the full question please?

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What is 81 to the power of 0.5?

Kisachek [45]

It would be 40.5 or 40 1/2

3 0

3 years ago

Read 2 more answers

Solve by completing the square.

AnnZ [28]

I wasn’t able to fit the text in the space provided, so, please see the attached papers.

6 0

3 years ago

Suppose the goal for mr. Luockwoods class had been 250 cans. Then 550 cans would have been what percent of the goal?

mr_godi [17]

Answer:

220%

Step-by-step explanation:

To find the percent divide the amout collected (550) by the goal (250)

550/250 = 2.2; convert to a %...220%

3 0

3 years ago

Of 1000 randomly selected cases of lung cancer, 823 resulted in death within 10 years.

Arada [10]

Answer:

a) $0.823 - 1.96\sqrt{\frac{0.823(1-0.823)}{1000}}=0.799$

$0.823 + 1.96\sqrt{\frac{0.823(1-0.823)}{1000}}=0.847$

The 95% confidence interval would be given by (0.799;0.847)

b) $n=\frac{0.823(1-0.823)}{(\frac{0.03}{1.96})^2}=621.79$

And rounded up we have that n=622

c) $n=\frac{0.5(1-0.5)}{(\frac{0.03}{1.96})^2}=1067.11$

And rounded up we have that n=1068

Step-by-step explanation:

Part a

$\hat p=\frac{823}{1000}=0.823$

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical value would be given by:

$z_{\alpha/2}=-1.96, z_{1-\alpha/2}=1.96$

The confidence interval for the mean is given by the following formula:

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

If we replace the values obtained we got:

$0.823 - 1.96\sqrt{\frac{0.823(1-0.823)}{1000}}=0.799$

$0.823 + 1.96\sqrt{\frac{0.823(1-0.823)}{1000}}=0.847$

The 95% confidence interval would be given by (0.799;0.847)

Part b

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.03$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

And replacing into equation (b) the values from part a we got:

$n=\frac{0.823(1-0.823)}{(\frac{0.03}{1.96})^2}=621.79$

And rounded up we have that n=622

Part c

$n=\frac{0.5(1-0.5)}{(\frac{0.03}{1.96})^2}=1067.11$

And rounded up we have that n=1068

5 0

3 years ago

A hiker walks along a path and comes to a cliff. He wants to find out how high the cliff is, so he ties a 110 foot cable to a ro

solmaris [256]

Answer:

B. sine; 46.5 feet high

Step-by-step explanation:

In this case, we use trigonometric ratio.

Assuming the horizontal ground, the cable and the height of the cliff forms a triangle,

The cable is the hypotenuse, the height of the cliff is opposite to the angle formed by the cable and the horizontal ground.

Thus; the most appropriate function is sine

Such that;

Sine θ = Opposite/Hypotenuse

Where; θ = 25°, opposite is the height of the cliff and hypotenuse is the cable, 110 ft

Therefore;

Sine 25° = Opp/ 110

Hence;

Opp = 110 ft × sine 25°

= 46.488 ft

= 46.5 ft

Therefore;

The function is Sine, and the height of the cliff is 46.5 ft high

3 0

3 years ago