MATH 231: Basic Statistics Homework #5 – Correlation and Regression: 1). Bi-lo Appliance Super-Store has outlets in several large metropolitan areas in New England. The general sales manager aired a commercial for a digital camera on selected local TV stations prior ro a sale starting on Saturday and ending on Sunday. She obtained the information for Saturday-Sunday digital camera sales at the various outlets and paired it with the number of times the advertisement was shown on local TV stations
Premium Statistics Regression analysis Linear regression
Chi-square requires that you use numerical values‚ not percentages or ratios. Then calculate 2 using this formula‚ as shown in Table B.1. Note that we get a value of 2.668 for 2. But what does this number mean? Here’s how to interpret the 2 value: 1. Determine degrees of freedom (df). Degrees of freedom can be calculated as the number of categories in the problem minus 1. In our example‚ there are two categories (green and yellow); therefore‚ there is I degree of freedom. 2. Determine a relative
Premium Variance Statistical hypothesis testing
1 CORRELATION & REGRESSION 1.0 Introduction Correlation and regression are concerned with measuring the linear relationship between two variables. 1.1 Scattergram It is not a graph at all‚ it looks at first glance like a series of dots placed haphazardly on a sheet of graph paper. The purpose of scattergram is to illustrate diagrammatically any relationship between two variables. (a) If the variables are related‚ what kind of relationship it is‚ linear or nonlinear
Premium Regression analysis Linear regression Spearman's rank correlation coefficient
A chi-squared test‚ also referred to as chi-square test or χw² test‚ is any statistical hypothesis test in which the sampling distribution of the test statistic is a chi-squared distribution when the null hypothesis is true. Also considered a chi-squared test is a test in which this is asymptotically true‚ meaning that the sampling distribution (if the null hypothesis is true) can be made to approximate a chi-squared distribution as closely as desired by making the sample size large enough. Some
Premium Statistical tests Variance Statistical hypothesis testing
edu/faculty/gerstman/StatPrimer/t-table.pdf (t table) Critical Values (Z) Level of Significance 1% 2% 4% 5% 10% Two Tailed ±2.56 ±2.32 ±2.05 ±1.96 ±1.64 Right tailed +2.32 +2.05 +1.75 +1.64 +1.28 Left tailed -2.32 -2.05 -1.75 -1.64 -1.28 Q1) A cinema hall has cold drinks fountain supplying Orange and Ditzy Colas. When the machine is turned on‚ it fills a 550ml cup with 500ml of the required drink. The manager has three problems. I) The clients have been complaining that the machine supplies less than 500ml
Premium Arithmetic mean Statistical hypothesis testing Profit
CHAPTER 13 CORRELATION AND REGRESSION ANALYSIS OUTLINE 4.1 Definition of Correlation Analysis 4.2 Scatter Diagram and Types of Relationships 4.3 Correlation Coefficient 4.4 Interpretation of Correlation Coefficient 4.5 Definition of Regression Analysis 4.6 Dependent and Independent Variables 4.7 Simple Linear Regression: Least Squares Method 4.8 Using the simple Linear Regression equation 4.9 Cautionary Notes and Limitations OBJECTIVES By the end of this
Premium Regression analysis Linear regression Statistics
Chi-Square Test Chi-square is a statistical test commonly used to compare observed data with data we would expect to obtain according to a specific hypothesis. For example‚ if‚ according to Mendel’s laws‚ you expected 10 of 20 offspring from a cross to be male and the actual observed number was 8 males‚ then you might want to know about the "goodness to fit" between the observed and expected. Were the deviations (differences between observed and expected) the result of chance‚ or were they due to
Premium Variance Statistical hypothesis testing Degrees of freedom
CHI-SQUARE TEST (χ²): Chi-square is a statistical test commonly used to compare observed data with data we would expect to obtain according to a specific hypothesis. For example‚ if‚ according to Mendel’s laws‚ you expected 10 of 20 offspring from a cross to be male and the actual observed number was 8 males‚ then you might want to know about the "goodness to fit" between the observed and expected. Were the deviations (differences between observed and expected) the result of chance‚ or were they
Premium Variance Statistical significance Errors and residuals in statistics
2.3. The Chi-Square Distribution One of the most important special cases of the gamma distribution is the chi-square distribution because the sum of the squares of independent normal random variables with mean zero and standard deviation one has a chi-square distribution. This section collects some basic properties of chi-square random variables‚ all of which are well known; see Hogg and Tanis [6]. A random variable X has a chi-square distribution with n degrees of freedom if it is a gamma
Premium Normal distribution Variance Probability theory
and data about infomercial products observed occurred by chance. According to Dr. Mirabella (2011)‚ if the observations are not equivalent to the expectations‚ then that is the time to observe and track more directly and gather more information. Chi-Square testing is one of the simplest techniques to use and the most applicable (Mirabella 2011). Therefore‚ we use hypothesis testing to see if we should dig further for more additional information. Even more‚ we utilize this test to show a comparison
Premium Advertising