a rhyolite rock has a volume of 9.5 ml. the density of the rock is 2.6 g/cm. what is the mass of the rock

Sung Lee invests $5,000 at age 18. He hopes the investment will be worth $20,000 when he turns 25. If the interest compounds con

Temka [501]

Answer:

19.8%

Step-by-step explanation:

We have the following formula for continuous compound interest:

A = P * e ^ (i * t)

Where:

A is the final value

P is the initial investment

i is the interest rate in decimal

t is time.

The time can be calculated as follows:

25 - 18 = 7

That is, the time corresponds to 7 years. In addition, A is 20,000 for A and P would be 5,000, we replace:

20000 = 5000 * e ^ (7 * i)

20000/5000 = e ^ (7 * i)

e ^ (7 * i) = 4

ln e ^ (7 * i) = ln 4

7 * i = ln 4

i = (ln 4) / 7

i = 0.198

Which means that the rounded percentage will be 19.8% per year

3 0

2 years ago

Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers have maintained careful records

madreJ [45]

Answer:

For this case we have the following info related to the time to prepare a return

$\mu =90 , \sigma =14$

And we select a sample size =49>30 and we are interested in determine the standard deviation for the sample mean. From the central limit theorem we know that the distribution for the sample mean $\bar X$ is given by:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

And the standard deviation would be:

$\sigma_{\bar X} =\frac{14}{\sqrt{49}}= 2$

And the best answer would be

b. 2 minutes

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The central limit theorem states that "if we have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large".

Solution to the problem

For this case we have the following info related to the time to prepare a return

$\mu =90 , \sigma =14$

And we select a sample size =49>30 and we are interested in determine the standard deviation for the sample mean. From the central limit theorem we know that the distribution for the sample mean $\bar X$ is given by:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

And the standard deviation would be:

$\sigma_{\bar X} =\frac{14}{\sqrt{49}}= 2$

And the best answer would be

b. 2 minutes

3 0

2 years ago

if my grade is 69% what will my grade be if i got a 3.3 of 4 on a essay and it's worth 25% of my grade?

juin [17]

Answer:

72.4%

Step-by-step explanation:

The essay is 25% of your grade, and the rest is 75% of your grade.

25 (3.3/4) + 75 (0.69) ≈ 72.4

6 0

3 years ago

Need help i have been stuck on this problem

liberstina [14]

The second one is correct

4 0

3 years ago

I don’t understand I’m zooted

soldi70 [24.7K]

Answer:

me either

Step-by-step explanation:

3 0

2 years ago