Lecture 04.
- 1. Biostatistics Lecture No 04 alfahadfarwa786@gmail.c Muhammad Alfahad Farwa Butt
- 2. Biostatistics Example: Suppose we walk in the nursery class of a school and we count the no. of books and copies that 45 students have in their bags. Suppose the no. of books and copies are 9, 9, 3, 5, 4, 7, 6, 7, 5, 6, 5, 5, 8, 7, 5, 5, 6, 6, 6, 9, 6, 7, 6, 6, 4, 5, 5, 6, 6, 6, 6, 7, 7, 6, 5, 4, 8, 7, 9, 9, 7, 8, 7, 7, 9. Construct a discrete frequency distribution. Solution: X Tally Frequency 3 | 1 4 ||| 3 5 |||| |||| 9 6 |||| |||| ||| 13 7 |||| |||| 10 8 ||| 3 9 |||| | 6 Total 45 alfahadfarwa786@gmail.c
- 3. Biostatistics Relative and cumulative frequency distribution X Frequency Relative/ %age Frequency Cumulative frequency 3 1 1/45 x 100 = 2.22% 1 4 3 3/45 x 100 = 6.67% 4 5 9 9/45 x 100 = 20% 13 6 13 13/45 x 100 = 28.89% 26 7 10 10/45 x 100 = 22.22% 36 8 3 3/45 x 100 = 6.67% 39 9 6 6/45 x 100 = 13.33% 45 Total 45 alfahadfarwa786@gmail.c
- 4. Biostatistics Graphical Representation Visual representation of statistical data in the form of points, lines, areas, is known as graphical representation. Such visual representation can be divided in to two groups. (i) Graph (ii) Diagram The basic difference between a graph and a diagram is that a graph is a representation of data by a continuous curve, while a diagram is any other one, two or three dimensional form of visual representation. TYPES OF DIAGRAM (i) Simple bar chart (ii) Multiple bar chart (iii) Component bar chart (iv) Pie diagrams alfahadfarwa786@gmail.c
- 5. Biostatistics Graphical Representation A simple bar chart is used to represent data involving only one variable classified quantitative/qualitative basis. A Simple bar chart consists of horizontal or vertical bars of equal widths and lengths proportional to the magnitudes of the observations. The space separating the bars should not exceed the width of the bar and should not be less than half of its width. Simple Bar Chart Years 1965 1966 1967 1968 1969 Turnover 35000 42000 43500 48000 48500 0 10000 20000 30000 40000 50000 60000 1965 1966 1967 1968 1969 Turnover alfahadfarwa786@gmail.c
- 6. Biostatistics Graphical Representation A multiple bar chart shows two or more characteristics corresponding to the values of a common variable. The length of bars are proportional to the values of characteristics. This is a good device for the comparison of two or three kinds of information. Multiple Bar Chart 1987 1988 1989 Locality-I 500 600 800 Locality-II 600 700 700 Locality-III 200 400 500 Example: Use multiple bar diagram to represent the production of wheat (thousand kg) in different localities of the Punjab for year 1987-1989. 0 100 200 300 400 500 600 700 800 900 1987 1988 1989 Series1 Series2 Series3 alfahadfarwa786@gmail.c
- 7. Biostatistics Graphical Representation In Component bar chart each bar is divided into two or more sections. The length of the bar represents the total and various sections represent the components of total. This type of graphical representation is used when we are interested in showing proportion of attribute and varieties of group. Component Bar Chart Division Both Gender Male Female Peshawar 64 33 31 Rawalpindi 40 21 19 Sargodha 60 32 28 Lahore 65 35 30 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Peshawar Rawalpindi Sargodha Lahore Series2 Series1 alfahadfarwa786@gmail.c
- 8. Biostatistics Graphical Representation A Pie diagram consists of a circle divided into sectors whose areas are proportional to the various parts into which the whole quantity is divided. The proportion that each component part bears to the whole quantity will be the corresponding proportion of 360o. component Part Angle = ─────────────── x 360 Whole quantity Example: Construct a Pie diagram to represent the total production(in thousand of kg) of different cops using urea fertilizer. Pie Diagram Crops Fertilizer Angle of sector Wheat 75 135 Sugarcane 80 144 Maize 30 54 37% 40% 15% 8% Fertilizer Wheat Sugarcane Maize Lentils A protector is used to make a pie chart. alfahadfarwa786@gmail.c