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自然科學 大學

想問3-9的a跟c

Problems 3-1. Explain the difference between *(a) random and systematic error. (b) constant and proportional error. *(c) absolute and relative error. (d) mean and median. *3-2. Suggest two sources of systematic error and two sources of random error in measuring the length of a 3-m table with a 1-m metal rule. 3-3. Name three types of systematic errors. *3-4. Describe at least three systematic errors that might occur while weighing a solid on an analytical balance. *3-5. Describe at least three ways in which a systematic error might occur while using a pipet to transfer a known volume of liquid. 3-6. Describe how systematic method errors may be detected. *3-7. What kind of systematic errors are detected by varying the sample size? 3-8. A method of analysis yields masses of gold that are low by 0.4 mg. Calculate the percent relative error caused by this result if the mass of gold in the sample is (a) 500 mg. (b) 250 mg. V(c) 125 mg. (d) 60 mg. 3-9. The method described in Problem 3-8 is to be used for the analysis of ores that assay about 1.2% gold. What minimum sample mass should be taken if the relative érror resulting from a 0.4-mg loss is not to exceed *(a) -0.1%? (b) -0.4%? (c) -0.8%? (d) - 1.1%? 3-10. The color change of a chemical indicator requires an overtitration of 0.03 mL. Calculate the error if the total volume of titrant is percent relative (a) 50.00 mL. (c) 25.0 mL. 3-11. A loss of 0.4 mg of Zn occurs in the course of an percent relative analysis for that element. Calculate the error due to this loss if the mass of Zn in the sample is *(b) 10.0 mL. (d) 30.0 mL. 190 (c) 188 (d) 4.52 x 103 4.63 x 103 4.53 x 10 ³ √6 *(a) 30 mg. (b) 100 mg. *(c) 300 mg. (d) 500 mg. 3-12. Find the mean and median of each of the following sets of data. Determine the deviation from the mean for each data point within the sets, and find the mean devi- Vation for each set. Use a spreadsheet if it is convenient. *(a) 0.0110 0.0105 (b) 24.53 0.0104 24.68 24.81 24.77 39.61 862 (f) 850 MA 3-13. Challenge Problem: Richards and W the molar mass of lithium and colle data. 24.73 Experiment 1 2 3 4 5 6 194 447 X 10 7 448 X 107 4.58 X 10 (a) Find the mean molar t workers. (b) Find the median molar ma (c) Assuming that the cam molar mass of lithium is the absolute ertor and of the mean value demi Willard. (d) Find in the chemical ues for the molar mus since 1910, and ag a table or spreadshera 1817 given in the a Richards and Willd. Com mass versus year to la of lithium has chang Suggest possible abruptly about 18 ant de (e) The incredibly deals Richards and W that major changes will occur. Disc calculation in pat (f) What factors ha since 1910? (g) How would you mass? 6See Chapter 2 of Applications of Microsoft Excel in Analytical Chemistry, 4th ed., for information about statistical 7T. W. Richards and H. H. Willard, J. Am. Chem. Soc., 1910, 32, 4, DOI: 10.1021/ja01919a002. built-in statistical functions. "Answers are provided at the end of the book for questions and problems marked with an asterisk The I of ₂ or inc rce of able vas error c often in individu ate resul data in rtainties. dimensio andom e analysts The result

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數學 國中

國中 數學 貧窮線 哈囉哈囉, 有沒有厲害の數學大大 閒閒沒事 可以幫忙解一下呢? 走過別錯過,快快來幫幫口憐落小的我..

聯合國永續發展目標(Sustainable Development Goals; SDGs)將「終結貧窮」列為 首要目標,希望在西元2030年前,消除所有地方的極端貧窮。這個極端貧窮的定義 就是「貧窮線(poverty line),簡單說就是指「貧窮門檻」,目前定義極端貧窮的門檻 是每生活費不到0.25 美元。有不少國家按照國內的生活水平畫下一條界線來釐定 貧窮與否,生活在這條線以下的便是貧窮人口,政府會提供相關的社會救助。 臺灣的社會救助法規定,「最低生活費(即貧窮線)的計算是家戶可 支配所得中 位數的60%,下圖為108 年各縣市家戶可 支配所得中位數折線圖,回答下列問題: (可用計算機計算,並四捨五入取至小數點後第二位) 0 9 108 年度家戶可支配所得中位數 萬元 140 124.36 120 105.36 109.79 100 94.33 100.3 85.30 98.08 80 78.18 79.51 77.37 70.01 63.94 63.02 84.31 84.25 72.53 71.65 65.71 66.15 60.05 60 40 20 0 新北市 臺北市 桃園市 臺中市 臺南市 高雄市 宜蘭縣 新竹縣 苗栗縣 彰化縣 南投縣 ·雲林縣 ·嘉義縣 - 屏東縣 - 臺東縣 - 花蓮縣 澎湖縣 「基隆市 新竹市 F 嘉義市 臺北市的貧窮線為多少元? 全臺家戶可支配所得中位數最低的是哪一個縣市?其貧窮線為多少元?

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