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3 years ago

If using the method of completing the square to solve the quadratic equation

Mathematics

1 answer:

jenyasd209 [6]3 years ago

4 0

You add half of the coefficient of x and square it.

What you do on one side,you must do it on the other.

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From a random sample of size 18, a researcher states that (11.1, 15.7) inches is a 90% confidence interval for mu, the mean leng

alexandr402 [8]

Complete Question

From a random sample of size 18, a researcher states that (11.1, 15.7) inches is a 90% confidence interval for mu, the mean length of bass caught in a small lake. A normal distribution was assumed. Using the 90% confidence interval obtain:

a. A point estimate of $\mu$ and its 90% margin of error.

b. A 95% confidence interval for $\mu$ .

Answer:

$\= x = 13.4$ . $E = 2.3$

$10.7 < \mu < 16.1$

Step-by-step explanation:

From the question we are told that

The sample size is n = 18

The 90% confidence interval is (11.1, 15.7)

Generally the point estimate of $\mu$ is mathematically evaluated as

$\= x = \frac{11.1 + 15.7 }{2}$

=> $\= x = 13.4$

Generally the margin of error is mathematically evaluated as

$E = \frac{15.7 - 11.1}{2 }$

=> $E = 2.3$

From the question we are told the confidence level is 90% , hence the level of significance is

$\alpha = (100 - 90 ) \%$

=> $\alpha = 0.10$

Generally from the normal distribution table the critical value of $\frac{\alpha }{2}$ is

$Z_{\frac{\alpha }{2} } = 1.645$

Generally the equation for the lower limit of the confidence interval is

$\= x - Z_{\frac{\alpha }{2} } * \frac{s}{\sqrt{18} } = 11.1$

=> $13.4 - 0.3877 s = 11.1$

=> $s = 5.932$

From the question we are told the confidence level is 95% , hence the level of significance is

$\alpha = (100 - 95 ) \%$

=> $\alpha = 0.05$

Generally from the normal distribution table the critical value of $\frac{\alpha }{2}$ is

$Z_{\frac{\alpha }{2} } = 1.96$

Generally the margin of error is mathematically represented as

$E = Z_{\frac{\alpha }{2} } * \frac{\sigma }{\sqrt{n} }$

=> $E = 1.96 * \frac{5.932}{\sqrt{18} }$

=> $E = 2.7$

Generally 95% confidence interval is mathematically represented as

$\= x -E < \mu < \=x +E$

=> $13.4 - 2.7 < \mu < 13.4 + 2.7$

=> $10.7 < \mu < 16.1$

3 0

3 years ago

I need help ASAP please

suter [353]

Answer:

sorry dude I don't know so sorry

8 0

3 years ago

Read 2 more answers

Find the average range. Round the mean and the average range to the nearest tenth. (Show all your work on scratch paper, then en

NISA [10]

3, 12, 15, 25, 30, 40The range is the difference between the greatest and smallest values:
range = 40 - 3 = 37

Thee average is the sum of elements divided by the number of elements:
average = (<span>3 + 12 + 15 + 25 + 30 + 40</span>)/6
average = 125/6 = 20.83

4 0

3 years ago

Plz help<br> 15 + (-8) =

Effectus [21]

Answer:

Step-by-step explanation:

15 + (-8)

The answer would be 7 because you are only taking 15 plus negative 8 which would technically be the same as taking 15 minus 8, which would be 7.

Hope this helps! Please mark as brainliest! Thanks! Let me know if you need anymore help! :D

6 0

3 years ago

Question 7

Anna35 [415]

Answer:

about 9 pounds, 7 ounces

Step-by-step explanation:

5 ounces per week

for 4 weeks

= 5 x 4 = 20 ounces gained thought these 4 weeks

Now add

8 Pounds, 3 ounces + 20 ounces = 9 pounds, 7 ounces

7 0

3 years ago