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Definition: Index numbers are statistical devices designed to measure the relative change in the level of variable or group of variables with respect to time, geographical location etc. In other words these are the numbers which express the value of a variable at any given period called “current period “as a percentage of the value of that variable at some standard period called “base period”. Here the variables may be 1. The price of a particular commodity like silver, iron or group of commodities like consumer goods, food, stuffs etc. 2. The volume of trade, exports, imports, agricultural and industrial production, sales in departmental store. 3. Cost of living of persons belonging to particular income group or profession etc. Methods of constructing index numbers: A large number of formulae have been derived for constructing index numbers. They can be 1) Unweighted indices  a) Simple aggregative method   b) Simple average of relatives.  2) Weighte...

  Statistical Quality Control** Meaning: S.Q.C. means planned collection & effective use of data for studying causes of variations in quality either as between processes, procedures, materials, machines etc. or over periods of time. By statistical quality control, we mean the various statistical methods used for the maintenance of the quality in manufactured product. Purpose of SQC: 1) To provide a basis for a better understanding of the variations that exists in quality characteristics. 2) To help directly or indirectly to improve quality. 3) To help in separating the assignable causes from the chance causes. 4) Better uniformity of quality. 5) Better utilization of raw materials. 6) More efficient use of equipment. 7) Less scrap and rework, hence lowering costs. 8) Better inspection. 9) Improved producer-consumer relations. Quality of Product: Quality product means good or excellent product. In industry, a quality product is one that fulfils custom...

  ⭐ Meaning of Quality 1️⃣ Conformance to specifications 2️⃣ Fitness for use 3️⃣ Customer satisfaction 4️⃣ Delighting the customer 5️⃣ Enchanting the customer (modern view) 🌟 Dimensions of Quality Attribute Meaning Performance How well it works Features Additional characteristics Reliability Consistency Conformance Meeting standards Durability Life of the product Serviceability Ease of repair Aesthetics Look & feel Reputation Brand trust 🔧 Quality Control A procedure to measure quality, compare with standards, and correct deviations. 🔹 Quality must be planned → achieved → controlled → improved continuously 📊 Statistical Quality Control (SQC) Applying statistical methods to control and improve product quality. 🎯 Purpose of SQC ✔ Reduce variation ✔ Improve quality ✔ Lower scrap & rework ✔ Better productivity & inspection 🖼 Seven Quality Control Tools (7-QC) Below are simplified visual representations to help you post: Tool Simple visual image Fl...

  PARTIAL CORRELATION   MULTIPLE CORRELATION   When the value of a variable is influenced by another variable, the relationship between them is a simple correlation. In a real-life situation, a variable may be influenced by many other variables. For example, the sales achieved for a product may depend on the income of the consumers, the price, the quality of the product, sales promotion techniques, the channels of distribution, etc. In this case, we have to consider the joint influence  of several independent variables on the dependent variable. Multiple correlations arise in this context. Coefficient Of Multiple Linear Correlations   The coefficient of multiple linear correlation is given in terms of the partial correlation coefficients as follows: