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Hunter-Best [27]

3 years ago

15

Which of the three runners have the fastest pace? Explain how you know.

1 answer:

GenaCL600 [577]3 years ago

6 0

What is the image, i can’t see it?

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The numerator of the given fraction is 4 less than the denominator. If 5 is added to both numerator and denominator, the resulti

Sholpan [36]

Answer:

5/9

Step-by-step explanation:

Let the denominator be x and numerator be y.

Given, numerator is 4 less than denominator

=> y = x - 4 ...(1)

When 5 is added to both:

Numerator = y + 5 , and, denominator = x + 5

Now their ratio is 5/7.

=> (y + 5)/(x + 5) = 5/7

=> 7(y + 5) = 5(x + 5)

=> 7y + 35 = 5x + 25

=> 7y - 5x = 25 - 35

=> 7(x - 4) - 5x = -10 {y=x-4}

=> 7x - 28 - 5x = -10

=> 2x = 18

=> x = 9

Thus,

Fraction is y/x = (x-4)/x = (9-4)/9 = 5/9

4 0

2 years ago

The graph of y = 4 – is shown.

Ratling [72]

Rather than try to select the correct answer without doing work, I'd rather do the work first and the matching later.

Given y = 4 - x, or y = 4 - 1x,

1) the y-intercept is (0,4).
2) this being a linear function, it has neither maximum nor minimum.
3) the x-intercept is found by letting y = 0 and solving for x: 0 = 4 - x; x - 4. The x-intercept is (4,0).

Which of the given statements is true?

7 0

2 years ago

Help me find the answer

solmaris [256]

I possibly think it is c that is what I got

8 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

<em>So, the 95% confidence interval is (46.4, 53.6)</em>

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

<em>So, the 95% confidence interval is (47.9, 52.1)</em>

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

In (a), we have:

$n = 30$ $E = 3.577$

In (b), we have:

$n = 90$ $E = 2.06584$

<em>Notice that the margin of error decreases when the sample size increases.</em>

4 0

3 years ago

How the use a parentheses in an equation affect the answer

seraphim [82]

Parentheses affect how equations are done.

EX. 1+1*4
4+1=5

VS

(1+1)*4
2*4=8

5 0

3 years ago