I need help with 5 plz also explain how to get it.

Manuel bought a balloon (that is a perfect sphere) with a radius of 2 \text{ cm}2 cm2, start text, space, c, m, end text. He wan

mote1985 [20]

Answer:

<h2>The required ratio is 8</h2>

Step-by-step explanation:

Volume of a sphere = $\frac{4}{3}\pi r^{3}$ where r is the radius of the sphere.

If manuel bought a balloon (that is a perfect sphere) with a radius of 2cm, the original volume of the sphere is expressed as;

Vo = $\frac{4}{3}\pi (2)^{3}$

$Vo = \frac{4}{3}\pi *8\\Vo = \frac{32 \pi}{3}$

If he wanted his balloon to be bigger and he blew 2 big breaths of air into the balloon, if each big breath increased the balloon's radius by 1cm, the total radius will be the initial radius of the sphere plus the new radius after expansion.

radius of current sphere = 2cm+(1cm+1cm) = 4cm

Volume of the current sphere Vc = $\frac{4}{3}\pi (4)^{3}$

$Vc = \frac{4}{3}\pi *64\\Vc = \frac{256 \pi}{3} \\$

The ratio of the current volume of the balloon Vc to the original volume of the balloon Vo will be expressed as;

Vc/Vo = $\frac{\frac{256\pi}{3} }{\frac{32\pi}{3} }$

$\frac{Vc}{Vo}=\frac{256\pi}{3}*\frac{3}{32\pi} \\\frac{Vc}{Vo}=\frac{256}{32}\\\frac{Vc}{Vo}= 8$

The required ratio is 8

3 0

3 years ago

Please show all work :)

yulyashka [42]

I might be wrong but I think the answer would be -x+2x+6 as a simplified version because if you use the equation (x+4•x+3)-3x(x+1)=a (or any letter you choose), you will get 3x+x^2+12+4x-3x-3x^2=y. Then, you can combine like terms:
4x-2x+12=a

7 0

3 years ago

(2x + 35)=(5x-22) what’s x

finlep [7]

Answer:

x=19

Step-by-step explanation:

5 0

3 years ago

Write your own example of a biased question. (for math)

Anni [7]

answer is

plz brainlist

8 0

3 years ago

Dual-energy X-ray absorptiometry (DXA) is a technique for measuring bone health. One of the most common measures is total body b

sesenic [268]

Answer:

$\bar d=\frac{\sum_{i=1}^n d_i}{n}=-0.001$

$s=\sqrt{\frac{\sum_{i=1}^n (x_i -\bar X)^2}{n-1}}=0.0095$

-The sample is too small to make judgments about skewness or symmetry.

H0: $\mu_{1}=\mu_{2}$

H1: $\mu_{1} \neq \mu_{2}$

$t=\frac{1.173-1.174}{\sqrt{\frac{0.1506^2}{8}+\frac{0.1495^2}{8}}}=-0.013$

$p_v =2*P(t_{(14)}$

So the p value is a very high value and using any significance level for example $\alpha=0.05, 0,1,0.15$ always $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and a we don't have a significant difference between the two means.

Step-by-step explanation:

First we need to find the difference defined as:

(Operator 1 minus Operator 2)

d1=1.326-1.323=0.003 d2=1.337-1.322=0.015

d3=1.079-1.073=0.006 d4=1.229-1.233=-0.004

d5=0.936-0.934=0.002 d6=1.009-1.019=-0.01

d7=1.179-1.184=-0.005 d8=1.289-1.304=-0.015

Now we can calculate the mean of differences given by:

$\bar d=\frac{\sum_{i=1}^n d_i}{n}=-0.001$

And for the sample deviation we can use the following formula:

$s=\sqrt{\frac{\sum_{i=1}^n (x_i -\bar X)^2}{n-1}}=0.0095$

Describe the distribution of these differences using words. (which one is correct)

We can plot the distribution of the differences with the folowing code in R

differences<-c(0.003,0.015,0.006,-0.004,0.002,-0.01,-0.005,-0.015)

hist(differences)

And we got the image attached. And we can see that the distribution is right skewed but we don't have anough info to provide a conclusion with just 8 differnences.

-The sample is too small to make judgments about skewness or symmetry.

Use a significance test to examine the null hypothesis that the two operators have the same mean. Give the test statistic. (Round your answer to three decimal places.)

$\bar X_{1}=1.173$ represent the mean for the operator 1

$\bar X_{2}=1.174$ represent the mean for the operator 2

$s_{1}=0.1506$ represent the sample standard deviation for the operator 1

$s_{2}=0.1495$ represent the sample standard deviation for the operator 2

$n_{1}=8$ sample size for the operator 1

$n_{2}=8$ sample size for the operator 2

t would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the means for the two groups are the same, the system of hypothesis would be:

H0: $\mu_{1}=\mu_{2}$

H1: $\mu_{1} \neq \mu_{2}$

If we analyze the size for the samples both are less than 30 so for this case is better apply a t test to compare means, and the statistic is given by:

$t=\frac{\bar X_{1}-\bar X_{2}}{\sqrt{\frac{s^2_{1}}{n_{1}}+\frac{s^2_{2}}{n_{2}}}}$ (1)

t-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.

Calculate the statistic

We can replace in formula (1) like this:

$t=\frac{1.173-1.174}{\sqrt{\frac{0.1506^2}{8}+\frac{0.1495^2}{8}}}=-0.013$

Statistical decision

For this case we don't have a significance level provided $\alpha$ , but we can calculate the p value for this test. The first step is calculate the degrees of freedom, on this case:

$df=n_{1}+n_{2}-2=8+8-2=14$

Since is a bilateral test the p value would be:

$p_v =2*P(t_{(14)}$

So the p value is a very high value and using any significance level for example $\alpha=0.05, 0,1,0.15$ always $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and a we don't have a significant difference between the two means.

8 0

3 years ago