BIO401 Help Notes by Baqir Hussain

Statistics

Topic 8

Definition: Methods of collection, organization and analysis of numerical information are collectively called statistics. Pieces of numerical and non-numerical information are called data. In order to collect data, you need to observe or measure some property; this property is called a variable.

Definition: A variable is qualitative if it is not possible for it to take a numerical value. A variable is quantitative if it can take a numerical value. A quantitative variable which can take any value in a given range is called a continuous variable. A quantitative variable which has clear steps between its possible values is called a discrete variable.

Types of Statistics: Descriptive Statistics comprises those methods concerned with collection and describing a set of data so as to yield meaningful information.

o Example: Summarized large amounts of data collected from the pool games of 2011 cricket world cup to provide immediate meaningful information concerning the performance of each team.

Inferential Statistics comprises those methods concerned with analysis of a subset of data leading to predictions or inferences about the entire set of data.

o Example: Suppose we collected data for 30 years regarding the average rainfall in the month of July in Lahore, and the amount came to be 3.3 centimeters. We make the inference that next year in the month of July we can expect between 3.2 and 3.4 centimeters of rain. Where can Statistics Contribute?

Business and Industry o

Manufacturing

Improve product quality Increase efficiency of processes o Marketing Conduct sample surveys Determine product viability Estimate advertisement effectiveness o Engineering Make consistent product Predict product life o Banking Estimate the risk of a company defaulting on loan Determine effective asset allocation for portfolios

Health and Medicine o Epidemiology Calculate cancer incidence rates Monitor disease outbreaks Study risk factors for various diseases o Public Health Design community efforts Education programs o Pharmacology Drug discovery, development, and approval Ensure validity of results in clinical trials o Genetics Identify potential indicators for specific diseases or traits ▪ Test gene modification for treatment of diseases

Natural Resources o Agriculture Evaluate differences in crop management Evaluate the best combinations of fertilizers, pesticides and densities of planting. o Ecology Study changes in local and global climate Develop strategies to improve the environment Study the impact of new industrial plants on surrounding ecology o Geography Evaluate the amount of rainfall one can expect for a given area based on longitude, latitude and distance from the sea.

Social and Natural Sciences o Physics Determine when an increase in the density of cosmic rays signals the presence of a supernova Conducting tests to determine existence of new particles. o Chemistry Predict shape of large molecules Analysis of mass spectrometry data o Biology Seek to better understand why insects cluster Identify genes related to a particular disease o Sociology Estimate the chances of a major war in the next five years Study the increase in rates of marriage failure Determine the characteristic of prisoners to study risk of them repeating criminal behavior. o Psychology Study the effects of narcotics on schizophrenia Determine if the existence of extrasensory perception can be demonstrated Evaluate the relationship between shyness and loneliness o Anthropology Determine the age of an archaeological site Analyze the percentage difference in body fat between urban and rural dwellers in Pakistan o Zoology Evaluate the differences in behavior of caged animals when they are outdoors and when they are indoors Determine what techniques are more effective in counting a given species of bird.

Education o Develop effective teaching strategies o Research appropriate and informative evaluation (testing) instruments o Identify risk factors for bullying, dropping out, failing o Identify factors contributing to a decrease/increase in student achievement o Study the proportion of graduates of various programs subsequently employed in their field of study

Government Media and Law o Government Agencies Design and implement effective sampling strategies Estimate the unemployment rate Track and report changes in the economy Regulations on stock trading, drug approval, pollution o Journalism Effective communication of statistical ideas to a broad audience Participation in education efforts o Expert Witness Testify in court cases involving DNA evidence, salary discrepancies, discrimination, and disease clusters