def extract_capability(capabilities):
    """
    Extracts relevant information from a list of capabilities.

    Args:
        capabilities (list): List of tuples containing capability data.

    Returns:
        tuple: A tuple containing the maximum value and its corresponding index.
    """
    max_value = max(capability[1] for capability in capabilities)
    max_index = [i for i, capability in enumerate(capabilities) if capability[1] == max_value][0]
    return (max_value, max_index)

# Example usage:
capabilities = [('v5_1768236144', 108217.11959687909, 721, 15009.3),
                ('v5_1768235312', 89435.63603047856, 734, 12184.7),
                ('v5_1768235983', 98379.19963352643, 987, 9967.5)]

print(extract_capability(capabilities))