Write the expression in its written form. 3/8×(1−13)

The average heights of a random sample of 400 people from a city is 1.75 m. It is known that the heights of the population are r

Dimas [21]

Answer:

The 95% confidence interval for the average heights of the population is between 1.7108m and 1.7892m.

Step-by-step explanation:

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

$\alpha = \frac{1-0.95}{2} = 0.025$

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

So it is z with a pvalue of $1-0.025 = 0.975$ , so $z = 1.96$

Now, find 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.

The standard deviation is the square root of the variance. So

$\sigma = \sqrt{0.16} = 0.4$

Then

$M = 1.96*\frac{0.4}{\sqrt{400}} = 0.0392$

The lower end of the interval is the mean subtracted by M. So it is 1.75 - 0.0392 = 1.7108m

The upper end of the interval is the mean added to M. So it is 1.75 + 0.0392 = 1.7892m

The 95% confidence interval for the average heights of the population is between 1.7108m and 1.7892m.

4 0

4 years ago

1. You are going to make one of these bags from a roll of cloth 1 meter wide. What

maks197457 [2]

Answer:

1 cm

You are going to make one of these bags from a roll of cloth 1 meter wide. What

is the shortest length that you need to cut from the roll for the bag?

Step-by-step explanation:

8 0

2 years ago

What number would you add to the equation below to complete the square?x2 + 4x = 0?

julia-pushkina [17]

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Equation
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x² + 4x = 0

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Add a constant
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x² + 4x + (4/2)² - (4/2)² = 0 ← Add 2² to form perfect square

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Evaluate bracket
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x² + 4x + 2² - 2² = 0

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Form the perfect square
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(x + 2)² = 4

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Square root both sides
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(x+2) = $\pm$ √4

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Evaluate the square root
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(x+2) = $\pm$ 2

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Solve x
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x = 2 - 2 or x = -2 - 2

x = 0 or -4

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Answer: The constant to add is 4 and the value of x = 0 or -4
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7 0

4 years ago

Alyssa has a goal to read a certain number of pages each week. So far she has read 60 pages, which is 15% of her goal. What is h

Arte-miy333 [17]

400 because divide 60 by 15 in order to get 1% of the unknown number, which is 4. Then, just multiply 4 by 100 to get 100% of the number, which equals 400.

4 0

3 years ago

Jose travels 34 miles from home to work on a daily basis. If she takes up a job that is 1 and 1/2 times as far as her old job, h

Olenka [21]

Answer:

51 miles

Step-by-step explanation:

To find how many miles it would be, we can multiply 34 by 1.5 because the new job is 1.5 times further.

34(1.5) = 51

7 0

3 years ago