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3 years ago

Find the sum. 3/7+-1/7

Mathematics

2 answers:

nadezda [96]3 years ago

6 0

Answer:

2/7

Step-by-step explanation:

set the equation as 3/7-1/7

by adding a negative to a positive you're subtracting

ycow [4]3 years ago

3 0

Answer:

2/7

Step-by-step explanation:

adding a negative is the same thing thing as subtracting a positive

3/7 + (-1/7) = 3/7 - 1/7 = 2/7

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The quotient of 5 less than a number and 6 is -4

Dovator [93]

-1 is the answer or your answer is gonna be false

7 0

3 years ago

Read 2 more answers

I really need help please

Leokris [45]

Answer:

So we have two given angles- 31* and 43*.

First we add those together.

31* + 43* = 74*

Then, we subtract that amount from 180*

180* - 74* = 106*

106* is the missing angle.

x106* - 31* = 75*

x106* + 43* = 149*

~Hope this helps~

6 0

3 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

3 years ago

If the perimeter of a rectangle is 124cm & the width is 35cm, what is the length?

-BARSIC- [3]

Answer:

l=27

b=2×35=70

2l=124-70=54

l=54/2=27

6 0

3 years ago

Please need help 20 points

Debora [2.8K]

Step-by-step explanation:

90+48=138

180-138=42

y=42

8 0

2 years ago