Solve the equation by completing the square. Round the square. Round to the nearest hundredth if necessary. x2

What is correct answer to -5-(-8)=

tino4ka555 [31]

Answer:

3

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

8p + 2q = -16<br> 2p - q=2

yKpoI14uk [10]

Answer:

p = -1 q = -4

Step-by-step explanation:

a system of eq and solve for p and q ??? can do :)

Eq. 1) 8p + 2q = - 16

Eq. 2) 2p - q = 2

use Eq .2 and solve for q

2p - 2 = q

plug into Eq.1 with q

8p +2(2p - 2) = - 16

8p +4p -4 = -16

12p = - 12

p = -1

plug -1 into Eq. 1 for p and solve for q

8(-1) + 2q = - 16

-8 + 2q = - 16

2q = -8

q = -4

8 0

3 years ago

A sample of 200 observations from the first population indicated that x1 is 170. A sample of 150 observations from the second po

igor_vitrenko [27]

Answer:

a) For this case the value of the significanceis $\alpha=0.05$ and $\alpha/2 =0.025$ , we need a value on the normal standard distribution thataccumulates 0.025 of the area on each tail and we got:

$z_{\alpha/2} =1.96$

If the calculated statistic $|z_{calc}| >1.96$ we can reject the null hypothesis at 5% of significance

b) Where $\hat p=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{170+110}{200+150}=0.8$

c) $z=\frac{0.85-0.733}{\sqrt{0.8(1-0.8)(\frac{1}{200}+\frac{1}{150})}}=2.708$

d) Since the calculated value satisfy this condition 2.708>1.96 we have enough evidence at 5% of significance that we have a significant difference between the two proportions analyzed.

Step-by-step explanation:

Data given and notation

$X_{1}=170$ represent the number of people with the characteristic 1

$X_{2}=110$ represent the number of people with the characteristic 2

$n_{1}=200$ sample 1 selected

$n_{2}=150$ sample 2 selected

$p_{1}=\frac{170}{200}=0.85$ represent the proportion estimated for the sample 1

$p_{2}=\frac{110}{150}=0.733$ represent the proportion estimated for the sample 2

$\hat p$ represent the pooled estimate of p

z would represent the statistic (variable of interest)

$p_v$ represent the value for the test (variable of interest)

$\alpha=0.05$ significance level given

Concepts and formulas to use

We need to conduct a hypothesis in order to check if is there is a difference between the two proportions, the system of hypothesis would be:

Null hypothesis: $p_{1} = p_{2}$

Alternative hypothesis: $p_{1} \neq p_{2}$

We need to apply a z test to compare proportions, and the statistic is given by:

$z=\frac{p_{1}-p_{2}}{\sqrt{\hat p (1-\hat p)(\frac{1}{n_{1}}+\frac{1}{n_{2}})}}$ (1)

a.State the decision rule.

For this case the value of the significanceis $\alpha=0.05$ and $\alpha/2 =0.025$ , we need a value on the normal standard distribution thataccumulates 0.025 of the area on each tail and we got:

$z_{\alpha/2} =1.96$

If the calculated statistic $|z_{calc}| >1.96$ we can reject the null hypothesis at 5% of significance

b. Compute the pooled proportion.

Where $\hat p=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{170+110}{200+150}=0.8$

c. Compute the value of the test statistic.

z-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

Replacing in formula (1) the values obtained we got this:

$z=\frac{0.85-0.733}{\sqrt{0.8(1-0.8)(\frac{1}{200}+\frac{1}{150})}}=2.708$

d. What is your decision regarding the null hypothesis?

Since the calculated value satisfy this condition 2.708>1.96 we have enough evidence at 5% of significance that we have a significant difference between the two proportions analyzed.

5 0

3 years ago

alice rode her bike the same number every day for 17 days she rode a tottle of 68miles during thes 17 days at this rate how mane

s344n2d4d5 [400]

4 miles!

68 divided by 17 = 4

7 0

3 years ago

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A baseball player hit 345 out of 1,000 balls pitched to him. What are the chances he gets a hit when he steps up to the plate?

Nimfa-mama [501]

Answer:

0.345

Step-by-step explanation:

hits/at-bats = 345/1000 = 0.345

The probability of a hit, any particular time he goes to bat. is 0.345.

The problem does not request any particular format, so 0.345 is a perfectly good answer.

In baseball, that is called a 'batting average', and is actually expressed that way - as a decimal - in a player's statistics.

On the other hand, if we did want to express the probability as a percentage, we would do this:

0.345 * 100% = (0.345 * 100) % = 34.5 %

Hope this helps

6 0

3 years ago

Solve the equation by completing the square. Round the square. Round to the nearest hundredth if necessary. x2 - 3x -12 =0