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2 years ago

Tim and Jim are working on a school project together. If he had to work by himself, it would take

Mathematics

1 answer:

Vladimir [108]2 years ago

4 0

Answer: 6 hours

Step-by-step explanation:

Given, Tim and Jim are working on a school project together.

Tim takes 10 hours to complete the school project.

If Jim worked alone, it would take him 15 hours

Let t be the time they both take if they work together.

Then, $\dfrac{1}{t}=\dfrac{1}{\text{Time taken by Tim}}+\dfrac{1}{\text{Time taken by jim}}$

$\Rightarrow\ \dfrac{1}{t}=\dfrac{1}{10}+\dfrac{1}{15}\\\\\Rightarrow\ \dfrac{1}{t}=\dfrac{3+2}{30}=\dfrac{5}{30}\\\\\Rightarrow\dfrac{1}{t}=\dfrac{1}{6}\\\\\Rightarrow t=6$

So, it will take 6 hours to complete the school project together .

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A poll found that 64% of a random sample of 1076 adults said they believe in ghosts.

Dennis_Churaev [7]

Answer:

Margin of error at 90% is 0.024

Margin of error at 99% is 0.037

Step-by-step explanation:

Sample size = 1076

A poll found that 64% of a random sample of 1076 adults said they believe in ghosts.

So, No. of adults said they believe ghosts = $\frac{64}{100} \times 1076=688.64\sim 688$

So, x = 688

n = 1076

$\widehat{p} = \frac{x}{n}$

$\widehat{p} = \frac{688}{1076}$

$\widehat{p} = 0.639$

$ME=z \times \sqrt{\frac{\widehat{p}(1-\widehat{p})}{n}}$

z at 90% confidence is 1.64

$ME=1.64 \times \sqrt{\frac{0.639(1-0.639)}{1076}}$

$ME=0.024$

So, margin of error at 90% is 0.024

Find the margin of error needed to be 99% confident.

z at 99% confidence is 2.58

$ME=2.58 \times \sqrt{\frac{0.639(1-0.639)}{1076}}$

$ME=0.024$

So, margin of error at 99% is 0.037

5 0

2 years ago

Traffic data revealed that 35 percent of automobiles traveling along a portion of an interstate highway were exceeding the legal

bija089 [108]

This is a typo and vaguely phrased. However, the closest to a direct solution is to think of it as follows: 35% of the cars are speeding. Out of these, 52% of the cars are also speeding. Hence, the result of cars that are both speeding and speed cars is 0.52*0.35=0.182

3 0

2 years ago

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Aaron drew the figure below for a school art project. What is the total area of the figure. Use the drop down menus to complete

Feliz [49]

Answer:

The trapezoid has a height of 3 inches, a shorter base measuring 2.75 inches, and a longer base measuring 4.25 inches. The total area of the entire figure is 33 square inches.

Step-by-step explanation:

I took the iready diagnostic :)

6 0

2 years ago

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Elisse has 20 meters of ribbon how many 15 cm of ribbon can be cut from it

ASHA 777 [7]

Answer:

133 pieces of 15cm can be cut from the ribbon.

Step-by-Step Explanation:

Length of ribbon = 20 meters

Length needed to be cut = 15 cm

We will convert meters into centimeters.

1 meter = 100 cm

20 meters = 2000 cm

Number of pieces = $\frac{2000}{15}$

Number of pieces = 133.33

Rounding off to nearest whole number = 133

Hence,

133 pieces of 15cm can be cut from the ribbon.

8 0

2 years ago

Hope researches the impact of one variable on another. She graphs the data from her research and sees that the data forms a shap

BigorU [14]

The correct answer is:

She can determine that while there is an association between the variables, there is no correlation, and she cannot determine causation.

Explanation:

Since there is an arch shape to her graph, we know that as one variable changes, the other changes in the same manner. This means there is an association between the variables.

However, since the graph is not linear, there is no correlation between the variables. Since there is no correlation, we cannot determine causation.

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2 years ago

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