Add datatype of data / given answers to metadata

We would like to add the datatype of the data / given answers to the metadata, e.g.: Spectrum questions are of type float or integer and need to explicitly converted from string to this datatype. First attempt to do this automatically did not work out unfortunately: series.convert_dtypes() and series.as_type(series.infer_objects().dtypes) detect floats as strings, which does not help. We would favour a solution which detects the datatype automatically or takes it from the metadata.