College

This problem involves several steps related to measures of dispersion and correlation. Let's structure and clarify it:

1. **Measures of Dispersion**

Calculate the following for the given data:

a) Variance

b) Mean Absolute Deviation

2. **Evaluate the Expressions for the Data Below**

Given data:

[tex]\[
\begin{align*}
X_1 &= 18, \\
X_2 &= 21, \\
X_3 &= 23, \\
X_4 &= 11, \\
X_5 &= 9, \\
X_6 &= 14, \\
X_7 &= 101, \\
X_8 &= 0, \\
X_9 &= 14, \\
X_{10} &= 55
\end{align*}
\][/tex]

Calculate the variance and mean absolute deviation using the provided data.

3. **Calculate Pearson's Correlation Coefficient**

Use the data from the following table to calculate Pearson's correlation coefficient:

[tex]\[
\begin{array}{|r|r|r|r|r|r|r|r|r|}
\hline
& 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 \\
\hline
X_1 & 45 & 18 & 63 & 105 & 0 & 0 & 111 & 29 \\
\hline
Y_f & 79 & 113 & 59 & 39 & 219 & 224 & 131 & 109 \\
\hline
\end{array}
\][/tex]

Calculate Pearson's correlation coefficient using the data provided in the table.

4. **Additional Instructions or Formulas**

There are some additional expressions that need context or proper formatting. Ensure to clearly list any further operations required for the calculations, such as:

[tex]\[
(2 \times 2i + 1)^2 = 1549
\][/tex]

Ensure all equations are correctly placed and formatted to avoid confusion.

Answer :

Certainly! Let's go through the process of finding the Pearson's correlation coefficient for the given data step-by-step.

### Step 1: Gather the Data
We have two sets of data:

- [tex]\( X \)[/tex] values: 45, 18, 63, 105, 0, 0, 111, 29
- [tex]\( Y \)[/tex] values: 79, 113, 59, 39, 219, 224, 131, 109

### Step 2: Calculate the Means
Calculate the mean of both sets of values.

Mean of [tex]\( X \)[/tex]:
[tex]\[
\text{Mean}_X = \frac{45 + 18 + 63 + 105 + 0 + 0 + 111 + 29}{8} = 46.375
\][/tex]

Mean of [tex]\( Y \)[/tex]:
[tex]\[
\text{Mean}_Y = \frac{79 + 113 + 59 + 39 + 219 + 224 + 131 + 109}{8} = 121.625
\][/tex]

### Step 3: Calculate the Covariance
The covariance shows how much two random variables vary together. Use the formula:
[tex]\[
\text{Covariance} = \frac{\sum{(x_i - \text{Mean}_X)(y_i - \text{Mean}_Y)}}{n}
\][/tex]

For our values, the covariance is:
[tex]\[
-1752.484375
\][/tex]

### Step 4: Calculate the Variances
Variance measures how far a set of numbers are spread out from their average value.

Variance of [tex]\( X \)[/tex]:
[tex]\[
\text{Variance}_X = \frac{\sum{(x_i - \text{Mean}_X)^2}}{n} = 1662.484375
\][/tex]

Variance of [tex]\( Y \)[/tex]:
[tex]\[
\text{Variance}_Y = \frac{\sum{(y_i - \text{Mean}_Y)^2}}{n} = 4106.234375
\][/tex]

### Step 5: Calculate Pearson's Correlation Coefficient
Pearson's correlation coefficient [tex]\( r \)[/tex] is calculated as follows:
[tex]\[
r = \frac{\text{Covariance}}{\sqrt{\text{Variance}_X \times \text{Variance}_Y}}
\][/tex]

Substituting the known values:
[tex]\[
r = \frac{-1752.484375}{\sqrt{1662.484375 \times 4106.234375}} = -0.6707389107098695
\][/tex]

### Conclusion
The Pearson's correlation coefficient for the given data is approximately [tex]\(-0.67\)[/tex]. This indicates a moderate negative relationship between the [tex]\( X \)[/tex] and [tex]\( Y \)[/tex] values in the dataset.