Table: rubicline_activity
Columns: specimen_weight_size
calculated_activity_bq
calculated_activity_ci
estimated_activity_gr_api
estimated_exposure_mrem_hr

Question: if the estimated exposure ( mrem )/hr* is 0.28, what is the specimen weight/size?
SQL: SELECT COUNT("specimen_weight_size") FROM rubicline_activity WHERE "estimated_exposure_mrem_hr" = '0.28'

Question: If the specimen weight /size is 1000 g / 8.79 cm, what is the estimated exposure ( mrem )/hr*?
SQL: SELECT "estimated_exposure_mrem_hr" FROM rubicline_activity WHERE "specimen_weight_size" = '1000 g / 8.79 cm'

Question: If the calculated activity (CI) is  4.96×10 −11, what is the specimen weight/size?
SQL: SELECT "specimen_weight_size" FROM rubicline_activity WHERE "calculated_activity_ci" = '4.96×10 −11'

Question: If the specimen weight/size is 1000 g / 8.79 cm, what is the calculated activity?
SQL: SELECT COUNT("calculated_activity_bq") FROM rubicline_activity WHERE "specimen_weight_size" = '1000 g / 8.79 cm'