Update xgboost_regressor.py (#9078)

* Update xgboost_regressor.py

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: rohan472000

Diff for: machine_learning/xgboost_regressor.py

@@ -27,7 +27,9 @@ def xgboost(
     ...    1.14300000e+03,  2.60958904e+00,  3.67800000e+01, -1.19780000e+02]]))
     array([[1.1139996]], dtype=float32)
     """
-    xgb = XGBRegressor(verbosity=0, random_state=42)
+    xgb = XGBRegressor(
+        verbosity=0, random_state=42, tree_method="exact", base_score=0.5
+    )
     xgb.fit(features, target)
     # Predict target for test data
     predictions = xgb.predict(test_features)