<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def convert_lat(Recs):
 """ uses lat, for age<5Ma, model_lat if present, else tries to use average_inc to estimate plat. """

    New = []
    for rec in Recs:
        if 'model_lat' in list(rec.keys()) and rec['model_lat'] != "":
            New.append(rec)
        elif 'average_age' in list(rec.keys()) and rec['average_age'] != "" and float(rec['average_age']) <= 5.:
            if 'site_lat' in list(rec.keys()) and rec['site_lat'] != "":
                rec['model_lat'] = rec['site_lat']
                New.append(rec)
        elif 'average_inc' in list(rec.keys()) and rec['average_inc'] != "":
            rec['model_lat'] = '%7.1f' % (plat(float(rec['average_inc'])))
            New.append(rec)
    return New