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1 year ago

Alan borrowed $570 for a new bed. He made 9 monthly payments to repay the loan. He

1 answer:

4 0

$~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad \begin{cases} I=\textit{interest earned}\dotfill &\$45\\ P=\textit{original amount deposited}\dotfill & \$570\\ r=rate\to r\%\to \frac{r}{100}\\ t=months\dotfill &9 \end{cases} \\\\\\ 45 = (570)(\frac{r}{100})(9)\implies \cfrac{45}{(570)(9)}=\cfrac{r}{100}\implies \cfrac{1}{114}=\cfrac{r}{100} \\\\\\ \cfrac{100}{114}=r\implies \stackrel{\%}{0.88}\approx r$

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Suppose you invested $10,000 part at 6% annual interest and the rest at 9% annual interest. If you received $684 in interest aft

victus00 [196]

Assuming simple interest (i.e. no compounding within first year), then
At 6%, interest = 10000*0.06=$600
At 9% interest = 10000*0.09 = $900

Two ways to find the ratio
method A. let x=proportion at 6%
then
600x+900(1-x)=684
Expand and solve
300x=900-684=216
x=216/300=0.72 or 72%
So 10000*0.72=7200 were invested at 6%
10000-7200=2800 were invested at 9%

method B: by proportions
Ratio of investments at 6% and 9%
= 900-684 : 684-600
=216 : 84
= 18 : 7
Amount invested at 6% = 18/(18+7) * 10000 = 0.72*10000 = 7200
Amount invested at 8% = 7/(18+7)*10000=0.28*10000=2800

5 0

3 years ago

How many weeks of data must be randomly sampled to estimate the mean weekly sales of a new line of athletic footwear? We want 98

Irina18 [472]

Answer:

$n=(\frac{2.33(1400)}{400})^2 =66.50 \approx 67$

So the answer for this case would be n=67 rounded up

Step-by-step explanation:

Information given

$\bar X$ represent the sample mean for the sample

$\mu$ population mean

$\sigma=1400$ represent the sample standard deviation

n represent the sample size

Solution to the problem

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (a)

And on this case we have that ME =400 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (b)

The critical value for 98% of confidence interval now can be founded using the normal distribution. And the critical value would be $z_{\alpha/2}=2.33$ , replacing into formula (b) we got:

$n=(\frac{2.33(1400)}{400})^2 =66.50 \approx 67$

So the answer for this case would be n=67 rounded up

8 0

3 years ago

The sum of 19 and a number X is equal to 22

madreJ [45]

x is 3. you would subtract 19 from 22 to get your answer

6 0

3 years ago

Read 2 more answers

Can someone please help me on this

docker41 [41]

Answer:

• The function is a linear function

• The function changes at a constant rate

Step-by-step explanation:

A graph of the function shows it to be a straight line (linear function). Such a function always changes at a constant rate. The line goes downward to the right, so the function is a decreasing function.

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"changes at a constant rate" and "linear function" are two different ways of saying the same thing: the graph of the function is a straight line.

3 0

2 years ago

If standard deviation of a given data is 5 and mean is 50 then coefficient of variation (C.V) is equal to *

torisob [31]

Answer:

Step-by-step explanation:

Coefficient of variation is a measure of dispersion, showing the variability of data in relation to the mean.

The Coefficient of variation compares the degree of variation between data points. The coefficient of variation is the ratio of mean to standard deviation. It is given by the formula:

Coefficient of variation = mean / standard deviation

Coefficient of variation = 50 / 5

Coefficient of variation = 10

4 0

3 years ago