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2 years ago

Please help middle school math

Mathematics

2 answers:

Effectus [21]2 years ago

8 0

Answer:greater than 7 cm

Step-by-step explanation:

Alex787 [66]2 years ago

5 0

Answer:

Greater than 7 cm.

Step-by-step explanation:

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The table shows the number of coils in different lengths of a spring.The spring next to the table shows an example of a 2 inch s

Nastasia [14]

The answer is A: 1 coil in a spring that is 7 inches long

i am not sure so correct me if i am wrong

hope this helps

4 0

2 years ago

184500 $ are to be divided between 2 people. One person has 80% of what the other person has. How much does each one receive in

Annette [7]

Given:

$184500 are to be divided between 2 people.

One person has 80% of what the other person has.

To find:

The amount each one receive in $.

Solution:

Let $x be the amount received by first person. Then,

Amount received by the second person = 80% of x

= 0.80x

Total amount = Amount received by first person + by second person

= $x+0.80x$

= $1.80x$

Total amount is 184500. So,

$1.80x=184500$

$x=\dfrac{184500}{1.80}$

$x=102500$

So, the amount received by the first person is $102,500.

$0.80x=0.80\times 102500$

$0.80x=82000$

So, the amount received by the second person is $82,000.

6 0

2 years ago

Simplify the expression: 14x-5(6x-7)+18

USPshnik [31]

Answer:

−16x+53

Step-by-step explanation:

Distribute

14−5(6−7)+18

↓

14−30+35+18

Add

14−30+35+18

↓

14−30+53

Combine like terms

14−30+53

↓

−16+53

8 0

2 years ago

5000 at 12% compound quarterly compared interest earned after 5 year's

hichkok12 [17]

Answer:

A = P(1+r÷100)^n

where A is amount after some days

r is the rate

n is the number of years

p is the principle (the amount of money before the interest)

A = 5000 ( 1 + 12÷100)^5

A = 8811.70

A = 8812

8 0

2 years ago

A simple random sample of items resulted in a sample mean of . The population standard deviation is . a. Compute the confidence

Varvara68 [4.7K]

Answer:

(a): The 95% confidence interval is (46.4, 53.6)

(b): The 95% confidence interval is (47.9, 52.1)

(c): Larger sample gives a smaller margin of error.

Step-by-step explanation:

Given

$n = 30$ -- sample size

$\bar x = 50$ -- sample mean

$\sigma = 10$ --- sample standard deviation

Solving (a): The confidence interval of the population mean

Calculate the standard error

$\sigma_x = \frac{\sigma}{\sqrt n}$

$\sigma_x = \frac{10}{\sqrt {30}}$

$\sigma_x = \frac{10}{5.478}$

$\sigma_x = 1.825$

The 95% confidence interval for the z value is:

$z = 1.960$

Calculate margin of error (E)

$E = z * \sigma_x$

$E = 1.960 * 1.825$

$E = 3.577$

The confidence bound is:

$Lower = \bar x - E$

$Lower = 50 - 3.577$

$Lower = 46.423$

$Lower = 46.4$ --- approximated

$Upper = \bar x + E$

$Upper = 50 + 3.577$

$Upper = 53.577$

$Upper = 53.6$ --- approximated

So, the 95% confidence interval is (46.4, 53.6)

Solving (b): The confidence interval of the population mean if mean = 90

First, calculate the standard error of the mean

$\sigma_x = \frac{\sigma}{\sqrt n}$

$\sigma_x = \frac{10}{\sqrt {90}}$

$\sigma_x = \frac{10}{9.49}$

$\sigma_x = 1.054$

The 95% confidence interval for the z value is:

$z = 1.960$

Calculate margin of error (E)

$E = z * \sigma_x$

$E = 1.960 * 1.054$

$E = 2.06584$

The confidence bound is:

$Lower = \bar x - E$

$Lower = 50 - 2.06584$

$Lower = 47.93416$

$Lower = 47.9$ --- approximated

$Upper = \bar x + E$

$Upper = 50 + 2.06584$

$Upper = 52.06584$

$Upper = 52.1$ --- approximated

So, the 95% confidence interval is (47.9, 52.1)

Solving (c): Effect of larger sample size on margin of error

In (a), we have:

$n = 30$ $E = 3.577$

In (b), we have:

$n = 90$ $E = 2.06584$

Notice that the margin of error decreases when the sample size increases.

4 0

2 years ago

Please help middle school math​

Please help middle school math