本研究以桃園縣高中職數學科教師為母群體，依學校規模分層隨機抽取11所學校的148位教師為研究對象，以問卷調查法研究教師於信賴區間的學科教學知識與教學現況，經收集資料分析後得結果如下：一、教師對於信賴區間也存在著迷思概念，尤其是教科書外的延伸概念，如不能正確掌握重覆取樣的意義及相信信心水準即機率等；二、求學時期曾修過統計學課程及具統計內容教學經驗之教師，其信賴區間的學科知識認知情況表現較佳，亦較贊同數學課程引入新統計概念之教學；三、教師對信賴區間概念的教學信心覺知較低，顯示教師較不具信心教好信賴區間概念；四、教師自覺具有足夠的學科教學專業知能時，於信賴區間的學科知識表現也愈好，反之亦然。

This study examined high school mathematics teachers in Taoyuan County. Based on school size, this study used a random sampling method to select 148 teachers from 11 schools. A questionnaire was designed to investigate teachers' pedagogical content knowledge (PCK) and teaching present situations of confidence interval (CI), and several statistical analyses were employed, yielding the following results: 1. High school mathematics teachers exhibit misconceptions on confidence interval, such as repeated sampling and believing that a confidence level equals probability, especially when the concept of confidence interval was not covered in the textbook. 2. Teachers who previously enrolled in statistics courses or taught related statistical lessons perform higher on subject knowledge of CI. They also agree more frequently that random sampling concepts should be introduced in curricula. 3. High school mathematics teachers perceive a low level of teaching confidence in CI; that is, most teachers do not agree that they have the confidence to teach this concept. 4. Teachers who exhibited a higher level of awareness of professional subject matter demonstrate superior understanding of CI, and vice versa.