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3 years ago

Should the quadratic formula be used to solve this question explain.x^2+4x-3=0

Mathematics

1 answer:

garik1379 [7]3 years ago

8 0

Answer:

Yes

Step-by-step explanation:

This equation does not factorise, so quadratic equation will be useful. It is easier than other methods that can be applied to this equation.

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Question 1 of 6

ruslelena [56]

Answer:

They could make at most 5 teams and its not possible to make everyone on team.

Step-by-step explanation:

If there are 4 players on a team, then we use 23 ÷ 4 = 5.75, 0.75 is not enough for 1, so there are 3 players remaining after making 5 teams.

3 0

2 years ago

Rose purchased 2 packs of red pens, 4 packs of black pens, and 3 packs of blue pens. The cost of each pack of pens was $2.50. Th

Nutka1998 [239]

Answer:

each pack costs 2.5, she bought x packs

x=2+4+3=9

she bought 9 packs

so 2.5 times 9=22.50

she spend $22.50

6 0

3 years ago

Read 2 more answers

Draw a line representing the rise and a line representing the run of the line State the slope of the line in simplest form

amid [387]

Slope is -5/3
I hope this helps :)

8 0

3 years ago

In a simple random sample of 1500 young Americans 1305 had earned a high school diploma.

inn [45]

Answer:

a) The standard error for this estimate of the percentage of all young Americans who earned a high school diploma is 0.87%.

b) The margin of error, using a 95% confidence level, for estimating the percentage of all young Americans who earned a high school diploma is of 1.71%.

c) The 95% confidence interval for the percentage of all young Americans who earned a high school diploma is (85.29%, 88.71%).

d) The lower bound of the confidence interval is above 80%, which means that the confidence interval supports the claim that the percentage of young Americans who cam high school diplomas has increased.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the z-score that has a p-value of $1 - \frac{\alpha}{2}$ .

Standard error:

The standard error is:

$s = \sqrt{\frac{\pi(1-\pi)}{n}}$

Margin of error:

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}} = zs$

The confidence interval is:

Sample proportion plus/minus margin of error. So

$(\pi - M, \pi + M)$

In a simple random sample of 1500 young Americans 1305 had earned a high school diploma.

This means that $n = 1500, \pi = \frac{1305}{1500} = 0.87$

a. What is the standard error for this estimate of the percentage of all young Americans who earned a high school diploma?

$s = \sqrt{\frac{\pi(1-\pi)}{n}} = \sqrt{\frac{0.87*0.13}{1500}} = 0.0087$

0.0087*100% = 0.87%.

The standard error for this estimate of the percentage of all young Americans who earned a high school diploma is 0.87%.

b. Find the margin of error, using a 95% confidence level, for estimating the percentage of all young Americans who earned a high school diploma.

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a p-value of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

Then

$M = zs = 1.96*0.0087 = 0.0171$

0.0171*100% = 1.71%

The margin of error, using a 95% confidence level, for estimating the percentage of all young Americans who earned a high school diploma is of 1.71%.

c. Report the 95% confidence interval for the percentage of all young Americans who earned a high school diploma.

87% - 1.71% = 85.29%

87% + 1.71% = 88.71%.

The 95% confidence interval for the percentage of all young Americans who earned a high school diploma is (85.29%, 88.71%).

d. Suppose that in the past, 80% of all young Americans earned high school diplomas. Does the confidence interval you found in part c support or refute the claim that the percentage of young Americans who cam high school diplomas has increased? Explain.

The lower bound of the confidence interval is above 80%, which means that the confidence interval supports the claim that the percentage of young Americans who cam high school diplomas has increased.

4 0

3 years ago

Whats the solution of a + 5 > -7?

rosijanka [135]

A + 5 > -7....subtract 5 from both sides
a > -7 - 5
a > - 12

4 0

3 years ago