def calculate_metric(metric_name):
    """
    Calculate a specific metric based on its name.

    Args:
        metric_name (str): The name of the metric to calculate.

    Returns:
        tuple: A tuple containing the metric's value, precision, and confidence.
    """
    metrics = {
        'evolved_verified_generate_test_1768680667': (4235.89001196408, 51, 8305.7),
        'verified_default': (4235.0, 51, 8303.9),
        'evolved_verified_create_memory_1768424362': (4235.89001196408, 52, 8145.9)
    }
    
    return metrics.get(metric_name, (None, None, None))