10.

\begin{tabular}{|l|l|l|l|l|l|l|l|l|l|l|}
\hline
x & 1.1 & 1.9 & 2.4 & 4.1 & 4.6 & 6 & 8.1 & 8.3 & 9.1 & 9.8 \\
\hline
y & 10 & 25 & 41 & 261 & 439 & 2,041 & 18,271 & 22,130 & 56,151 & 119,550 \\
\hline
\end{tabular}

a. Is there a correlation?

b. If yes, what function family?

c. What is the equation that describes this data?

d. If linear, what is the correlation coefficient? What does this mean?

e. What is the coefficient of determination?

f. Is this equation a good one to use for predictions? Why?



Answer :

Sure, let's analyze the given data step by step.

### Step 1: Determine if there is a correlation

We first need to calculate the correlation coefficient between the x and y values.

The correlation coefficient for the given data is approximately [tex]\(0.7376\)[/tex]. This value indicates a moderate to strong positive correlation between the x and y values.

### Step 2: Identify the function family

Given that we want to find the best fit for the data, we analyze different types of functions. For this data set, a polynomial function fits well. In this case, we specifically found that a quadratic polynomial (second-degree polynomial) is appropriate.

### Step 3: Equation of the polynomial

The equation of the polynomial that describes the data can be written from the coefficients that were found. The equation is:
[tex]\[ y = 2967.65624054x^2 - 23570.00078929x + 34386.66256147 \][/tex]

### Step 4: Discussing the correlation coefficient

Since the function is polynomial and not linear, the correlation coefficient was used to initially check for any relationship. The moderate to strong positive correlation coefficient (~0.7376) indicates that as x increases, y increases in a somewhat proportional manner, though not perfectly due to the non-linearity.

### Step 5: Coefficient of determination

The coefficient of determination (denoted as [tex]\(R^2\)[/tex]) indicates how well the polynomial model fits the data. In this case, [tex]\(R^2\)[/tex] is approximately 0.8240.

### Step 6: Assessing the model's suitability for predictions

An [tex]\(R^2\)[/tex] value of 0.8240 suggests that about 82.4% of the variability in the y-values can be explained by the polynomial model. This is generally considered a good fit, meaning the model is reasonably accurate.

### Conclusion

- Correlation: Yes, there is a moderate to strong positive correlation.
- Function Family: Polynomial.
- Equation: [tex]\( y = 2967.65624054x^2 - 23570.00078929x + 34386.66256147 \)[/tex]
- Correlation Coefficient (if linear): The polynomial correlation coefficient wouldn't be applicable in the same sense, but if we still consider the linear correlation, it’s approximately 0.7376.
- What does this mean? The positive correlation indicates a relationship between x and y where increases in x are associated with increases in y.
- Coefficient of Determination: [tex]\(R^2 = 0.8240\)[/tex]
- Good for Predictions? Yes, because an [tex]\(R^2\)[/tex] value of 0.8240 indicates a strong explanatory power of the polynomial model, making it reliable for making predictions based on this data.