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3 years ago

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Does anyone know this? There are 25 students names in a hat. You choose 5 names. Three are boys names and two are girls names. H

ow many of the 25 names would you expect to be boys names?

2 answers:

SVETLANKA909090 [29]3 years ago

7 0

The answer is probably 15 if you use ratios. So 3x5 equals 15

Nady [450]3 years ago

5 0

Answer:

I would expect there to be 15 boy names and 10 girl names.

Step-by-step explanation:

There is a 3 to 2 ratio between boy and girl names, and the only numbers that add up to 25 with that ratio are 15 and 10

You might be interested in

I need help, the options are: Corresponding Angles, Vertical Angles, Alternate interior angles, linear pair, alternate exterior

stiks02 [169]

Answer:

✔️ <1 and <3 => Vertical angles

✔️<2 and <6 => alternate exterior angles

✔️<2 and <4 => corresponding angles

✔️<3 and <7 => alternate interior angles.

✔️<4 and <3 => consecutive interior angles.

✔️<7 and <6 => linear pair angles.

Step-by-step explanation:

✔️ <1 and <3 are opposite angles formed when two straight lines intersect. They both share the same vertex. Thus, they are vertical angles, which are congruent to each other.

<1 and <3 are vertical angles.

✔️<2 and <6 are alternate exterior angles.

<2 and <6 both lie outside the straight lines cut across by the transversal, and they also lie in the side of the transversal alternating each other

✔️<2 and <4 are corresponding angles.

They both take the same position on the same side of the transversal.

✔️<3 and <7 are alternate interior angles.

They are alternating angles along the transversal that are located just within the two lines intersected by the transversal.

✔️<4 and <3 are consecutive interior angles.

They are angles on the same side of the transversal but lie within the two straight lines intercepted by the transversal.

✔️<7 and <6 are linear pair angles.

They are angles on a straight line, and sum up to 180°.

3 0

3 years ago

In a random sample of 75 American women age 18 to 30, 26 agreed with the statement that a woman should have the right to a legal

ddd [48]

Answer:

a) $z=\frac{0.347-0.328}{\sqrt{0.338(1-0.338)(\frac{1}{75}+\frac{1}{64})}}=0.236$

$p_v =2*P(Z>0.236)=0.813$

If we compare the p value and using any significance level for example $\alpha=0.01$ always $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can say that we don't have significant differences between the two proportions.

b) We are confident at 99% that the difference between the two proportions is between $-0.188 \leq p_B -p_A \leq 0.226$

Step-by-step explanation:

Previous concepts and data given

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$p_A$ represent the real population proportion of women age 18 to 30 agreed with the statement that a woman should have the right to a legal abortion for any reason

$\hat p_A =\frac{26}{75}=0.347$ represent the estimated proportion of women age 18 to 30 agreed with the statement that a woman should have the right to a legal abortion for any reason

$n_A=75$ is the sample size for A

$p_B$ represent the real population proportion for women age 58 to 70 agreed with the statement that a woman should have the right to a legal abortion for any reason

$\hat p_B =\frac{21}{64}=0.328$ represent the estimated proportion of women age 58 to 70 agreed with the statement that a woman should have the right to a legal abortion for any reason

$n_B=64$ is the sample size required for B

$z$ represent the critical value for the margin of error and for the statisitc

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

Part a

We need to conduct a hypothesis in order to check if the proportion are equal, the system of hypothesis would be:

Null hypothesis: $p_{A} = p_{B}$

Alternative hypothesis: $p_{A} \neq p_{B}$

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

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

Where $\hat p=\frac{X_{A}+X_{B}}{n_{A}+n_{B}}=\frac{26+21}{75+64}=0.338$

Calculate the statistic

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

$z=\frac{0.347-0.328}{\sqrt{0.338(1-0.338)(\frac{1}{75}+\frac{1}{64})}}=0.236$

Statistical decision

Since is a two sided test the p value would be:

$p_v =2*P(Z>0.236)=0.813$

If we compare the p value and using any significance level for example $\alpha=0.01$ always $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can say that we don't have significant differences between the two proportions.

Part b

The confidence interval for the difference of two proportions would be given by this formula

$(\hat p_A -\hat p_B) \pm z_{\alpha/2} \sqrt{\frac{\hat p_A(1-\hat p_A)}{n_A} +\frac{\hat p_B (1-\hat p_B)}{n_B}}$

For the 99% confidence interval the value of $\alpha=1-0.99=0.01$ and $\alpha/2=0.005$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=2.58$

And replacing into the confidence interval formula we got:

$(0.347-0.328) - 2.58 \sqrt{\frac{0.347(1-0.347)}{75} +\frac{0.328(1-0.328)}{64}}=-0.188$

$(0.347-0.328) + 2.58 \sqrt{\frac{0.347(1-0.347)}{75} +\frac{0.328(1-0.328)}{64}}=0.226$

And the 99% confidence interval for the difference of proportions would be given (-0.188;0.226).

We are confident at 99% that the difference between the two proportions is between $-0.188 \leq p_B -p_A \leq 0.226$

5 0

3 years ago

Help me will mark brainliest

yulyashka [42]

Answer:

1/(-3y^3/x)^4

= 1/(-3)^4*(y^3)^4/x^4

= 1/81y^12/x^4

=x^4/81y^12

A

Step-by-step explanation:

4 0

3 years ago

Write an equation in slope-intercept<br> form through (-8,9) through (-6,-6).

fgiga [73]

Answer:

A

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

Professor Hartwick finds that people who tend to score low on one variable tend to score low on another variable. Professor Hart

garri49 [273]

Answer:

Option C) a positive correlation.

Step-by-step explanation:

We are given the following in the question:

" People who tend to score low on one variable tend to score low on another variable."

Correlation:

Correlation is a technique that help us to find or define a linear relationship between two variables.
It is a measure of linear relationship between two quantities.
A positive correlation means that an increase in one quantity leads to an increase in another quantity or decrease in one quantity leads to decrease in another quantity.
A negative correlation means with increase in one quantity the other quantity decreases.
+1 tells about a a perfect positive linear relationship and −1 indicates a perfect negative linear relationship.

Since, for the given case with decrease in one variable other also decreases, thus, it is an example of positive correlation. Thus, the correlation coefficient cannot be less than or equal to zero.

Thus, the correct answer is

Option C) a positive correlation.

8 0

3 years ago