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MariettaO [177]

2 years ago

10

Translate the following into an algebraic expression: If it would take Mark m hours to clean the house alone and with his brothe

r Sam they can clean the house together in t hours. How many hours would it have taken Sam if he was working alone?

1 answer:

umka2103 [35]2 years ago

6 0

Answer:

t=m

Step-by-step explanation:

You might be interested in

Solve the following equation: 2(4^2 + 10) =

lesantik [10]

Answer:

52

Step-by-step explanation:

2(4^2 + 10) =

We do what's in the parenthesis first.

4^2 = 16 and 16+10 =26.

2(26)

= 52

3 0

3 years ago

Read 2 more answers

7 2/15+52/3+9 13/15 a. 20 2/3 B.21 10/15 C.21 2/3 D.22 2/3 pls do i will mark brainlessness

Andreyy89

Answer:

101/3 or 33 2/3

Step-by-step explanation:

7 2/15=107/15

9 13/15=138/15

107/15+52/3+138/15

107/15+138/15+52/3

245/15+52/3

245/15+260/15

505/15

simplify,

101/3

8 0

2 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

2 years ago

Determine side x. Round to the nearest unit. 20 9 12 5

tatyana61 [14]

Answer:

12

Step-by-step explanation:

First, you will have to use trigonometry. Since the side of the triangleis the opposite of the angle 53 and the hypotenuse, you will use sin.

Sin 53 degrees = opposite side / hypotenuse side.

The opposite side is x and the hypotenuse side equals 15.

sin53= x/15

15 ( sin 53 ) =x

x= 11.97953

Round

x=12

6 0

2 years ago

A family is relocating from St. Louis, Missouri, to California. Due to an increasing inventory of houses in St. Louis, it is tak

Dafna1 [17]

Answer:

a. Assume that the population has a normal distribution.

b. The 90% confidence interval of the mean sale time for all homes in the neighborhood is between 219.31 days and 240.69 days.

Step-by-step explanation:

Question a:

We have to assume normality.

Question b:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.9}{2} = 0.05$

Now, we have to find z in the Ztable as such z has a pvalue of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.05 = 0.95$ , so Z = 1.645.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

$M = 1.645\frac{35}{\sqrt{29}} = 10.69$

The lower end of the interval is the sample mean subtracted by M. So it is 230 - 10.69 = 219.31 days.

The upper end of the interval is the sample mean added to M. So it is 230 + 10.69 = 240.69 days.

The 90% confidence interval of the mean sale time for all homes in the neighborhood is between 219.31 days and 240.69 days.

7 0

2 years ago