Find the work done when a crane lifts a -pound boulder through a vertical distance of feet. Round to the nearest foot-pound.

Working alone, Darryl can mop a warehouse in 11 hours. Elisa can mop the same warehouse in 9

Harrizon [31]

Answer:

≈ 5 hours

Step-by-step explanation:

<u>Time needed if they work together:</u>

1 / (1/11 + 1/9) =
1/ (20 / 99) =
99/20 ≈ 5 hours

3 0

2 years ago

Need help ASAP!!! HAVE QUIZ TOMORROW

Serjik [45]

To solve these problems, you usually have a favor the numerator. For example, on #7, label your terms, 1 from m^2 is A, -6m from -6 is B and your constant, 8, is C. Next you have to find out what two numbers can be multiplied to give you for C term but can also add together to give you your B term. For this specific problem, -4 and -2 gives you 8 and also adds to be -6. After that, you put your -4 and -2 into their own separate parentheses along with the M from M^2. It should look this like: (m-4)(m-2)/(m-2). Now you notice that the binomial on the bottom and one of the binomials on top is the exact same, so you would cancel that out and your answer would be (m-4).

6 0

3 years ago

How do you solve age word problems

Anna71 [15]

These videos might help you

https://www.khanacademy.org/math/algebra/systems-of-linear-equations/systems-of-linear-equations-wor...

5 0

3 years ago

Suppose that a jewelry store tracked the amount of emeralds they sold each week to more accurately estimate how many emeralds to

RUDIKE [14]

Answer:

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

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

And for this case the 95% confidence interval is given by (2.13; 2.37)

We have a point of estimate for the sample mean with this formula:

$\bar X = \frac{Upper+ Lower}{2}= \frac{3.37+2.13}{2}= 2.75$

And for the margin of error we have the following estimation:

$ME= \frac{Upper -Lower}{2}= \frac{3.37-2.13}{2}= 0.62$

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

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".

$\bar X$ represent the sample mean

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

Solution to the problem

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

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

And for this case the 95% confidence interval is given by (2.13; 2.37)

We have a point of estimate for the sample mean with this formula:

$\bar X = \frac{Upper+ Lower}{2}= \frac{3.37+2.13}{2}= 2.75$

And for the margin of error we have the following estimation:

$ME= \frac{Upper -Lower}{2}= \frac{3.37-2.13}{2}= 0.62$

5 0

3 years ago

12.6 + 4m = 9.6 + 8m

Sergeu [11.5K]

Answer:

3 = 4m or 0.75 = m

Step-by-step explanation:

12.6 + 4m = 9.6 + 8m

Subtract 4m from both sides of the equation

12.6 = 9.6 + 4m

Subtract 9.6 from both sides of the equation

3 = 4m

Divide by four on both sides of the equation

0.75 = m

I Hope That This Helps! :)

7 0

3 years ago

Read 2 more answers

Find the work done when a crane lifts a ​-pound boulder through a vertical distance of feet. Round to the nearest​ foot-pound.

Find the work done when a crane lifts a -pound boulder through a vertical distance of feet. Round to the nearest foot-pound.