|Other Retailer||Price Checked Time||Their Price in NZD||Our Price|
|Amazon UK||2 days ago||99.47||$75.85||You save $23.62|
|Amazon US||22 days ago||85.38||$75.85||You save $9.53|
AUTHOR BIO Robert I. Kabacoff, is a research methodologist, statistical consultant, and software developer with over 25 years of experience working with organizations in health care, financial services, manufacturing, behavioral sciences, government, and academia. As Vice President of Research for Management Research Group, he provides research and statistical programming for organizations in North America, Western Europe, Africa, and the Pacific Rim. For the past four years, he has managed an R tutorial website that receives approximately 11,000 visitors a day.