Course Materials: Biostatistics

BIOSTATISTICS Brometty deals cuith all metry measurement types of meartinement in biological experiment, when the principles of statistics arce applied to study of organisms or thing system, the freedy is called brostaticies. Areas of application of biostatistics (1) Medicine (3) Agriculture (5) Popectation biology. (3) fisheries (4) Pharmacy (6) conservation science Collection and classification of data Biological data: The first method of biostatistice it the collection of dates which can be asfined as a set of measurement on one or more observatiorial unit that happens to interest ass Example- If cwe are interested to know asual length of enake cobra then length of different cobras are called data. Depending upon the source, data can be classified into two types:- primary data Secondary data Primary data * these are the data which are collected for the first time and original In nature. These are in the shape of raw materials to cwhich statistical methods aree appited for the pourpose of analysis. and interpretation example bata obtained by a research student in the growth rate of fish by conducting some experiments. secondary data There one the data which have already boon collesred by come other persons and conich have passed through the steutisiacel machine at least once. •These are waarty in the shape of finfined products, since they. have been treated Statistically in soma form or other Example-data obtained from meterdogical department used by water resources, forest, agricueterre are being being Graphical representation of data + A diagram is a visual form for the presentation of biological data • There are many ways to represent data graphically.. 1. simple bar diagram 97 2. Mizztiple bar diagram 6. Pictogram 3. Rendom/component/subdfulded 7. Histogram 4. Percentage scabatulded 8. frequency polygon 5. Pie diagram 9. frequency curve 10. egive Frequency Polygon • The figere obtained by joining the middle points of the top of the rectangle in a histogram, by straight line is known as frequency polygon. + It is generally used in a frequency distribution in which the clast interval are equal. *It has no spectal significance but given an idea about the shape of a frequency distribution.tands • In order to complete the drawing of a frequency polygon the two end points of it should be of the empty distritection. goin to base ine at the classes at the both end of the midpoints frequency Histogram • A histogram is a diagramatic representation of frequency distribution euthich contains a set of rectangles, each constructed to represent the size of the class interval ky its width in each class interval by its height. and the frequcerey *the area of each rectangle is proportional to the frequency in the respective class interval and the total area proportional to the total frequency. of the histogram is * A histogram is used to illustrats a frequency distribution. *the class friterval is always on the y-axls. taken on the x-axis and the frequency • Each class is represented by a distance on the scale • The distance for each rectangle on the x-axis remain the same, In case the class interval are uniform. *Then one can get any gap. a series of consequtively placed rectangle coithoxet Sampling Method • In biological, study of the population is very essential but the whole population cannot be brought to the Lab... * Practical acternative is by the method of sampling from sample we collect, information regarding different perander of population. there are two methods of sampling. 1. Random campling 2. Non-Random sampling 1. Random sampling It is also knocon as probability sampling * scientific techniques of drawing samples from the population according to some laws of chance in which each unit has some definite pre-assigned probability being selected in the Sample. • There are y types of random. sampling (1) simple random sampling (ii) stratified random sampling (ii) lyttematic random sampling (iv) Muttierage random sampling ① Simple Random Sampling :- In this method each and every membere of the population has an equal chance of been inclueded in the sample. ②stratified Tandom sampling :- * In this method population is divided into strata, before the sample is drawn. • Strata are so designed that they donot ove overlap. ③ Systematic random sampling :- Every alimentary unit of the population is arranged in a order and the sample cenits are regular interval. distributed at equal Multistage random sampling:- • sample of alimentary units are selected in stages sample of dutter is selected and of alimentary unit is selected. among 1st a them a sample 2. Non random sampling those which do not provide every Hem th the universe cuith a known chance of being included in the Pample There are 5 types of non-random sampling. 1. Parposive non random sampling 2. cluster non random sampling 3. Queta nort random sampling 4 convenience non random sampling 5. fequential non random sampling 1. Piurposive non random sampling :- • Method of sampling by chich a sample is drawn from a population based entirely on personal judgement of the investigator. So it is also knoO QA judgement sampling. 2. cluster non random sampling- *It involves arranging alimenterous item in a population in to heterogenexes Seebgroups ore clusters that are of sample population. represent as the overal 3. Quota non random sampling- *It is fixed according to the basis parameter of the population. * Determine earlier and each Investigator is of number of alimentary arits assigned cwith quota 4. convenience non random sampling- Sample is obtained by selecting convient sample from the population 5. sequentias non random sampling- The member of samples. drawn one after another from the population depending on the rescue of cererer population another. one aften Morit of mode •st its cervenity mond entity centersuch resteralical tatuation. • It is easily eunderstood." ya walice achtch always exist in the sentes. pemerit of mode • It is not hased on all the observation of a series. • merce it is ravety used in any higher biological and scientific proepere. MEDIAN median re the value of the middle then of a series arranged in acenting or descending orden. In case of discreate series of the number of item (n) es odd, then median coill be the value of the Item. If the number of item is arethematic mean of the value even then median coill be the th Flem and 7+17th Item For that the data must be arranged in ascending or descending ordert.