Giving brainliest ! *easy*

Carlotta is making blue and orange necklaces in several lengths. For each necklace, her ratio of blue beads to orange beads is 3

fenix001 [56]

36 blue beads and there would be 24 orange 3:2

6 0

2 years ago

So this is the first question/ discussion i have to do.

Rainbow [258]

Answer:

arrange 3+4=5

Step-by-step explanation:

because 3 square = 9 and 4 square =16 and their sum is 25 and the square of 5 is 25 . both are same .

Hence proved

3 0

2 years ago

A drug company is considering marketing a new local anesthetic. The effective time of the anesthetic the drug company is current

lapo4ka [179]

Using the z-distribution, we have that:

a)

The hypothesis test is:

$H_0: \mu = 7.4$

$H_1: \mu < 7.4$

The p-value is of 0.0668.

The critical value is $z^{\ast} = -1.28$

b) Since the test statistic is less than the critical value for the left-tailed test, there is enough evidence to conclude that the null hypothesis will be rejected.

Item a:

At the null hypothesis, it is tested if the mean is of 7.4 minutes, that is:

$H_0: \mu = 7.4$

At the alternative hypothesis, it is tested if the mean is lower than 7.4 minutes, that is:

$H_1: \mu < 7.4$

We have the standard deviation for the population, hence, the z-distribution is used.

The test statistic is given by:

$z = \frac{\overline{x} - \mu}{\frac{\sigma}{\sqrt{n}}}$

The parameters are:

$\overline{x}$ is the sample mean.

$\mu$ is the value tested at the null hypothesis.

$\sigma$ is the standard deviation of the sample.

n is the sample size.

For this problem, the values of the parameters are: $\overline{x} = 7.1, \mu = 7.4, \sigma = 1.2, n = 36$ .

Hence, the value of the test statistic is:

$z = \frac{\overline{x} - \mu}{\frac{\sigma}{\sqrt{n}}}$

$z = \frac{7.1 - 7.4}{\frac{1.2}{\sqrt{36}}}$

$z = -1.5$

Using a z-distribution calculator, the p-value is of 0.0668.

Also using a calculator, considering a left-tailed test, as we are testing if the mean is less than a value, the critical value with a significance level of 0.1 is of $z^{\ast} = -1.28$ .

Item b:

Since the test statistic is less than the critical value for the left-tailed test, there is enough evidence to conclude that the null hypothesis will be rejected.

You can learn more about the use of the z-distribution to test an hypothesis at brainly.com/question/16313918

5 0

1 year ago

There were 16 sandwiches on a tray for a lunch meeting. After the meeting, 3 were left. How many sandwiches were eaten?

kifflom [539]

Answer:

13

Step-by-step explanation:

16-3+= 13

6 0

2 years ago

Read the following excerpts from the New York Times (December 17, 1996) article Chance of Heart Attack Increases for Those Who S

nataly862011 [7]

Answer:

1. B

2. A

3. A

4. A

Step-by-step explanation:

Hello!

The study claimed that subjects who suffer depression are more likely to have a heart attack than those who are not depressed.

1551 persons were interviewed as part of the experiment and classified according to their answers in two groups "suffered depression" and "didn't suffer depression"

Afterward, the researchers looked up the medical history of all 1551 subjects and recorded how many of them had heard issues.

1.

An observational study is one where the researcher only determines the variables he wants to study without controlling or influencing any factor of the population of interest. Because there is no interference from the researchers, there is a high risk that confounding factors may affect the conclusions of it. These studies are usually precursors to experimental tests, it allows the researcher to have an idea of the association between the two variables but you cannot establish causal relationships from them.

This is an example of an observational study, the researcher merely recorded the variables of interest without interfering with any aspects that may influence them. (For example diet or exercise habits of the subjects)

2. and 3.

The objective of the study is to determine if "depression" causes "disposition to heart attacks"

The explanatory variable is "depression status of the subject" since it is what is suspected to influence over the heart condition of said subject and "heart attack status" is the response variable.

4.

Of the 1551 subjects originally studied, 444 were classified as depressed, of these 27 had heard attacks. You can calculate the "proportion of subjects that suffered depression and had heart attacks" as:

p': 27/444= 0.06 ⇒ 6%

Since this value was obtained from the sample, it is an estimation of the population parameter, also called statistic.

I hope it helps!

4 0

2 years ago