4. (15 points) A company that is looking at the time to failure of the parts (days) it uses decides to look
at an alternative supplier of the product. The data for the current supplier and for the new supplier are shown here.
Assume that the data are normally distributed.
3.在材料破壞性檢驗的低碳鋼拉伸試驗時,試片在試驗過程中其尺寸的變化及受力符號為:L0 試片原始長度、L 試片拉斷時長度、A0 試片原始斷面積、A 試片拉斷時斷面積、Py為開始 降伏前的最大負荷、Pu為試片所能承受的最大負荷,相關之應力應變圖如下所示;請說明下 列名詞的意義,並將對應點 a、b、c 標示於圖上。作答時請將上圖描繪於答案卷上)