Discover a world of knowledge and community-driven answers at IDNLearn.com today. Join our interactive Q&A community and get reliable, detailed answers from experienced professionals across a variety of topics.

Bone mineral density and cola consumption have been recorded for a sample of patients. Let [tex]x[/tex] represent the number of colas consumed per week and [tex]y[/tex] the bone mineral density in grams per cubic centimeter.

\begin{tabular}{|r|r|}
\hline
Number of Colas & Bone Mineral Density \\
\hline
2 & 0.8958 \\
\hline
3 & 0.886 \\
\hline
4 & 0.8792 \\
\hline
5 & 0.8864 \\
\hline
6 & 0.8696 \\
\hline
7 & 0.8668 \\
\hline
8 & 0.877 \\
\hline
9 & 0.8692 \\
\hline
10 & 0.8624 \\
\hline
11 & 0.8636 \\
\hline
12 & 0.8628 \\
\hline
13 & 0.853 \\
\hline
\end{tabular}

Round answers to at least 4 decimal places.

a) Find the regression equation [tex]\hat{y} = \square 0.8995 - 0.0058x[/tex]

b) According to the linear regression equation, the bone density of someone who drinks 21 colas per week is [tex]\square \frac{\text{grams}}{\text{cm}^3}[/tex].

c) Find the correlation coefficient, be careful with the sign. [tex]\square -0.7963[/tex]

d) What is the correct alternative hypothesis? [tex]\square \mu \ne 0[/tex]

e) What is the [tex]p[/tex]-value? [tex]\square 0.0019[/tex]

f) Is this correlation statistically significant at the [tex]5\%[/tex] significance level? [tex]\square \text{Yes}[/tex]

Question Help:
Message instructor


Sagot :

### Solution:

First, we will address each part of the question step-by-step.

#### a) Finding the Regression Equation

To find the regression equation of the form [tex]\(\hat{y} = b_0 + b_1x\)[/tex]:

- The intercept ([tex]\(b_0\)[/tex]), given as approximately 0.8962.
- The slope ([tex]\(b_1\)[/tex]), given as approximately -0.003146.

Thus, the regression equation is:
[tex]\[ \hat{y} = 0.8962 - 0.0031x \][/tex]

#### b) Predicting Bone Density for 21 Colas per Week

Using the regression equation [tex]\(\hat{y} = 0.8962 - 0.0031x\)[/tex], we substitute [tex]\(x = 21\)[/tex] to predict the bone density:

[tex]\[ \hat{y} = 0.8962 - 0.0031 \times 21 \][/tex]
[tex]\[ \hat{y} = 0.8962 - 0.0651 \][/tex]
[tex]\[ \hat{y} = 0.8311 \, \text{grams per cubic centimeter} \][/tex]

#### c) Finding the Correlation Coefficient

The correlation coefficient measures the strength and direction of the linear relationship between two variables. The given correlation coefficient is:
[tex]\[ r = -0.9150 \][/tex]

#### d) Determining the Correct Alternative Hypothesis

The alternative hypothesis in this context examines whether the slope of the regression line is different from zero (indicating some relationship between the number of colas and bone mineral density). The correct alternative hypothesis is:
[tex]\[ H_a: \mu \neq 0 \][/tex]

#### e) Finding the [tex]\(p\)[/tex]-value

The [tex]\(p\)[/tex]-value helps in determining the statistical significance of our results. The given [tex]\(p\)[/tex]-value is:
[tex]\[ p \text{-value} = 0.0 \][/tex]

#### f) Determining Statistical Significance at the 5% Level

To determine if the correlation is statistically significant at the 5% significance level, we compare the [tex]\(p\)[/tex]-value to 0.05. Since the [tex]\(p\)[/tex]-value given is 0.0, which is less than 0.05, we conclude that the correlation is statistically significant at the 5% level:
[tex]\[ \text{Statistically significant} = \text{True} \][/tex]

### Summary of Answers:

Let's now update each component based on the given values and results.

a) Regression equation: [tex]\(\hat{y} = 0.8962 - 0.0031x\)[/tex]

b) Bone density prediction for 21 colas per week: [tex]\(\hat{y} = 0.8311 \, \text{grams per cubic centimeter}\)[/tex]

c) Correlation coefficient: [tex]\(r = -0.9150\)[/tex]

d) Correct alternative hypothesis: [tex]\(H_a: \mu \neq 0\)[/tex]

e) [tex]\(p\)[/tex]-value: [tex]\(0.0\)[/tex]

f) Statistically significant at 5% level: Yes (True)

We can complete the solution for the problem with exactly these values.