A medical experiment on tumor growth gives the following data table.
2
\begin{tabular}{cc}
\hline$x$ & $y$ \\
34 & 38 \\
68 & 46 \\
89 & 52 \\
97 & 65 \\
101 & 77 \\
\hline
\end{tabular}

The least squares regression line was found. Using technology, it was determined that the total sum of squares (SST) was 961.2 and the sum of squares of regression (SSR) was 740.1. Calculate $R^{2}$, rounded to three decimal places.

Provide your answer below:

Step 1 ：Given the sum of squares of regression (SSR) as 740.1 and the total sum of squares (SST) as 961.2.

Step 2 ：The coefficient of determination, denoted R^2, is a key output of regression analysis. It is interpreted as the proportion of the variance in the dependent variable that is predictable from the independent variable(s).

Step 3 ：R^2 is computed as the ratio of the sum of squares of regression (SSR) to the total sum of squares (SST). So, we can calculate R^2 as SSR/SST.

Step 4 ：Substitute the given values into the formula: R^2 = SSR/SST = 740.1/961.2 = 0.7699750312109862

Step 5 ：Rounding to three decimal places, we get R^2 = 0.770

Step 6 ：Final Answer: The value of R^2, rounded to three decimal places, is \(\boxed{0.770}\)