Slope of -3 and y intercept 7 in slope-intercept form.

A reaction takes 4 min 28 sec to complete. Which of the following is a correct representation of that time period?

Ostrovityanka [42]

Using proportions, the correct representation of that time period is of 4.47 minutes.

<h3>What is a proportion?</h3>

A proportion is a fraction of a total amount, and the measures are related using a rule of three. Due to this, relations between variables, either direct(when both increase or both decrease) or inverse proportional(when one increases and the other decreases, or vice versa), can be built to find the desired measures in the problem, or equations to find these measures.

We have that one minute has 60 seconds, hence the proportion that the 28 seconds correspond of a minute is:

28/60 = 0.47 min.

Hence the correct representation of that time period is of 4.47 minutes.

More can be learned about proportions at brainly.com/question/24372153

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7 0

2 years ago

The half-life of a radioactive isotope is the time it takes for a quantity of the isotope to be reduced to half its initial mass

Setler [38]

Answer:

$\boxed{6.875 \text{\: grams}}$

Step-by-step explanation:

Half-lives are how long it takes for half of a substance to decay. If you start with a certain amount and it decays for a certain amount of half-lives, you are dividing by $2^{x}$ , where <em>x</em> is equal to the amount of half-lives.

In order to solve this question, simply divide the starting value by 2 raised to the value of half-lives.

$\large\boxed{\frac{220}{2^{5}}=6.875\text{\: grams}}$

7 0

3 years ago

Describe the congruence transformation that maps quadrilateral ABCD to quadrilateral A'B'C'D'.

umka2103 [35]

Answer:

B) 90 degrees clockwise rotation

8 0

3 years ago

In a recent study, researchers found that 31 out of 150 boys aged 7-13 were overweight or obese. On the basis of this study can

AURORKA [14]

Answer:

1) Null hypothesis: $p \leq 0.15$

Alternative hypothesis: $p > 0.15$

2) The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

3) $z_{crit}= 1.64$

And the rejection zone would be $z>1.64$

4) Calculate the statistic

$z=\frac{0.207 -0.15}{\sqrt{\frac{0.15(1-0.15)}{150}}}=1.955$

5) Statistical decision

For this case our calculated value is on the rejection zone, so we have enough evidence to reject the null hypothesis at 5% of significance and we can conclude that the true proportion is higher than 0.15

Step-by-step explanation:

Data given and notation

n=150 represent the random sample taken

X=21 represent the boys overweight

$\hat p=\frac{31}{150}=0.207$ estimated proportion of boy overweigth

$p_o=0.15$ is the value that we want to test

$\alpha=0.05$ represent the significance level

Confidence=95% or 0.95

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest)

1) Concepts and formulas to use

We need to conduct a hypothesis in order to test the true proportion of boys obese is higher than 0.15.:

Null hypothesis: $p \leq 0.15$

Alternative hypothesis: $p > 0.15$

When we conduct a proportion test we need to use the z statistic, and the is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

2) The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

3) Decision rule

For this case we need a value on the normal standard distribution who accumulates 0.05 of the area on the right tail and on this case this value is:

$z_{crit}= 1.64$

And the rejection zone would be $z>1.64$

4) Calculate the statistic

Since we have all the info requires we can replace in formula (1) like this:

$z=\frac{0.207 -0.15}{\sqrt{\frac{0.15(1-0.15)}{150}}}=1.955$

5) Statistical decision

For this case our calculated value is on the rejection zone, so we have enough evidence to reject the null hypothesis at 5% of significance and we can conclude that the true proportion is higher than 0.15

6 0

3 years ago

If a polygon is a triangle, then it is either acute or obtuse. Which is the hypothesis of the conditional?

Scorpion4ik [409]

Answer:

idk cuh

Step-by-step explanation:

7 0

3 years ago