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3 years ago

7

The class ________ is the breadth, or range, of numbers we plan to put into each class of a frequency distribution using grou

ped quantitative data.

1 answer:

NikAS [45]3 years ago

4 0

Answer:

Width

Step-by-step explanation:

When we have quantitative data it is grouped in classes. There are three ways in which the data can be grouped they are:

Single value grouping where each class has one distinct value.

In Cutpoint grouping is used when the observations have decimal points

In Limit grouping a classes are set based on a specified range of values. Here limit grouping is being done and the range of each class is called width.

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What is r in this equation? <br>πr^2=42π

kupik [55]

R in this equation refers to the radius

${\pi r}^{2} = 42\pi \\ {r}^{2} = \frac{42\pi}{\pi} \\ r = \sqrt{42 } \\ r = 6.480740698$

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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.

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3 years ago

7) Newton sees 50 frogs in the morning, and 7 fewer frogs in the

mario62 [17]

Answer:

93

Step-by-step explanation:

8 0

3 years ago

Write the factors of a2-b2.

nignag [31]

Answer:
(a + b) and (a - b)

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3 years ago

if a cylinder with height 9 inches and radius r is filled with water, it can fill a certain pitcher. how many of these pitchers

dalvyx [7]

Answer:

4 pitchers

Step-by-step explanation:

we know that

The volume of a cylinder is equal to

$V=\pi r^{2}h$

step 1

Find the volume of the cylinder with height 9 inches and radius r

substitute the given values

$V_1=\pi r^{2}(9)$

$V_1=9\pi r^{2}\ in^3$

step 2

Find the volume of the cylinder with height 9 inches and radius 2r

substitute the given values

$V_2=\pi (2r)^{2}(9)$

$V_2=36\pi r^{2}\ in^3$

step 3

we know that

The volume of the cylinder 1 can fill a certain pitcher,

so

The volume of the pitcher is the same that the volume of cylinder 1

therefore

the number of pitchers that can be filled by the second cylinder is equal to divide the volume of the second cylinder by the volume of the first cylinder

$\frac{36\pi r^{2}}{9\pi r^{2}}=4\ pitchers$

3 0

3 years ago