The test statistic (t) can be calculated as 4.63. Explanation: Given that the correlation coefficient (r) is 0.857 and the sample size (n) is 12, we can use the formula for the t-statistic in a correlation test, which is t = r * sqrt[(n-2) / (1 - r^2)]. Substituting the given values into the formula, we get: t = 0.857 sqrt[(12-2) / (1 - (0.857)^2)] t = 0.857 sqrt[10 / (1 - 0.734)] t = 0.857 sqrt[10 / 0.266] t = 0.857 sqrt[37.594] t = 0.857 * 6.13 t = 4.63 So, the test statistic (t) is approximately 4.63. This value can be compared to a critical value from a t-distribution table (with degrees of freedom = n - 2 = 10) to determine whether the correlation is statistically significant