Twelve Means Nine Things: An Item-Response Analysis of Fit Outcomes for 246 Garments Labelled 8 to 18 Across Nine Retailers, Against a Size Availability Index That Counts Labels StockedResolving to Twelve Means Nine Things: An Item-Response Analysis of Fit Outcomes for 246 Garments Labelled 8 to 18 Across Nine Retailers, Against a Size Availability Index That Counts Labels Stocked…