Ở chương này, BẠN SẼ HỌC KỸ THUẬT CÓ GIÁ để phát triển các dự báo và đề án phân loại. Những kỹ thuật này đã được sử dụng để dự báo doanh số bán các bộ phận của Công ty Honda Motors, dịch bệnh tại các trung tâm đào tạo hải quân, để phát triển các tiêu chí giữ các tân binh biển, | In this chapter you will learn valuable techniques with which to develop forecasts and classification schemes. These techniques have been used to forecast parts sales by the Honda Motors Company and epidemics at naval training centers to develop criteria for retention of marine recruits optimal tariffs for Federal Express and multitiered pricing plans for Delta Airlines. And these are just examples in which I ve been personally involved . MODELS A model in statistics is simply a way of expressing a quantitative relationship between one variable usually referred to as the dependent variable and one or more other variables often referred to as the predictors. We began our text with a reference to Boyle s law for the behavior of perfect gases V KT P. In this version of Boyle s law V the volume of the gas is the dependent variable T the temperature of the gas and P the pressure exerted on and by the gas are the predictors and K known as Boyle s constant is the coefficient of the ratio T P. An even more familiar relationship is that between the distance S traveled in t hours and the velocity V of the vehicle in which we are traveling S Vt. Here S is the dependent variable and Vand t are predictors. If we travel at a velocity of 60mph for 3 hours we can plot the distance we travel over time with Excel as follows 1. Put the labels Time and Distance at the head of the first two columns. 2. Put the values 1 2 and 3 in the first column. Introduction to Statistics Through Resampling Methods Microsoft Office Excel by Phillip I. Good Copyright 2005 John Wiley Sons Inc. 156 STATISTICS THROUGH RESAMPLING METHODS AND MICROSOFT OFFICE EXCEL Distance expected at 60mph straight line vs. distance FIGURE observed. 3. Put the formula 60 A3 in cell B3 and copy it down the column. 4. Create a scatterplot using Excel s Chart Wizard. Select XY Scatter but use the option Scatter with data points connected by smoothed lines without markers. I attempted .
