Quantitative Techniques Worksheet Datta Meghe Institute of Management Studies Atrey Layout, Nagpur-440022 2014 UNIT 1- CENTRAL TENDENCY AND DISPERSION Arithmetic MEAN 1. 2. Calculate Arithmetic mean of the following data. S. N 1 2 3 4 5 6 X 110 100 105 125 162 148 Calculate Arithmetic mean of the following data. S.N A B C D E X 0.82 0.96 1.01 1.80 1.90 7 119 8 110 F 2.09 9 111 G 2.11 10 114 11 12 164 120 Soln:- 124 H 2.98 I J 3.05 3.99 Soln:- 2.072 3. Following are the heights of 100 students in a class. Calculate arithmetic mean of the data. Roll N. 1 2 3 4 5 6 7 8 9 10 11 12 Heights in 60 61 63 64 66 67 68 69 70 71 72 73 Inches No. of 2 3 4 9 18 20 17 14 5 3 3 2 Students Soln:- 67.06 4. Calculate arithmetic mean for the following frequency distribution. Class 0-2 2-4 4-6 6-8 8-10 10-12 Interval Frequency 3 7 12 18 20 14 5. 6. 7. 8. 9. DMIMS 12-14 13 Calculate arithmetic mean for the following frequency distribution. Class 0-5 5-10 10-15 15-20 20-25 25-30 30-35 Interval Frequency 15 24 28 40 50 30 25 Calculate arithmetic mean by using the following data. Class 35-39 30-34 25-29 20-24 Interval Frequency 6 10 14 20 Calculate the missing frequencies. No. of Accidents 0 1 Frequency 46 ? 2 ? 5 26 3 25 6 34 35-40 40-45 20 24 30 5-9 24 Soln:- 21.05 70-78 78-85 10 5 8 9 45-50 10 8 Soln:- 22.34 10-14 7 40 16-18 10 3 Soln:- 9.14 15-19 Calculate arithmetic mean for the following frequency distribution. Class 0-10 10-25 25-35 35-50 50-59 Interval Frequency 5 10 16 30 19 Calculate the mean from the following data. Value 1 2 3 4 Frequency 21 30 28 40 14-16 85-100 5 Soln:- 46.95 9 10 15 27 Soln:- 5.72 4 5 10 5 Soln:- f1=76, f2=38 Page 2 10. By using the following information find out the missing values. Savings(Rs.) 95 100 112 115 118 Depositors 5 10 18 22 16 ? 14 122 125 6 5 Soln:- 114.66 130 4 11. Following information is about the working hours of 200 machines in a factory. Calculate average working hours of the factory by using arithmetic mean. Working Hours No. of Machines Less than 100 10 Less than 200 30 Less than 300 55 Less than 400 86 Less than 500 126 Less than 600 150 Less than 700 169 Less than 800 185 Less than 900 195 Less than 1000 200 Soln:- 447 12. From the following information pertaining to 150 workers. Calculate average wage paid to workers. Wages Rs. No. of Workers More than 75 150 More than 85 140 More than 95 115 More than 105 95 More than 115 70 More than 125 60 More than 135 40 More than 145 25 Soln:- 116.33 13. Calculate weighted average for the following data. It is not the same as simple arithmetic mean. Comment on the result. Income (Rs.) 5000 3400 1500 800 750 500 Weights 5 8 10 15 25 47 Soln:- 1104.1 14. An expedition team traveled for one week and covered a distance in the following way. What is the average speed of the team? Days Mon Tue Wed Thu Fri Sat Sun Speed KM 50 61 58 55 65 60 62 No. of Hrs 8 9 9 10 7 8 7 Soln:- 58.45 15. From the following find out the mean profits. Profits per shop No. of Shops Rs. 100-200 10 200-300 18 300-400 20 400-500 26 500-600 30 600-700 28 700-800 18 Soln:- 486 DMIMS Page 3 MEDIAN 16. The following are the details of production of 12 units. Calculate median. S.No 1 2 3 4 5 6 7 8 Production 25 16 30 18 19 35 22 34 9 23 10 17 17. The following are the daily wages of 187 workers in a factory. Calculate median. Wages 38 45 50 56 58 60 65 70 78 (Rs.) Workers 5 8 15 28 30 32 25 22 12 18. 19. 20. 21. 22. DMIMS 11 12 33 20 Soln:- 22.5 80 90 6 4 Soln:- 60 Following are the defects found in different operations in 260 units in a year in a company. Calculate median. Defects No. of Units 2.5-4.5 20 4.5-6.5 25 6.5-8.5 30 8.5-10.5 42 10.5-12.5 55 12.5-14.5 38 14.5-16.5 21 16.5-18.5 19 18.5-20.5 10 Soln:- 10.97 Calculate the median for information given below. Class 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 Frequency 11 15 19 21 35 30 12 10 8 4 3 Soln:- 27.07 Calculate the median for the following frequency distribution. Expenditure Rs, 00 No. of Units Less than 15 5 Less than 25 12 Less than 35 21 Less than 45 40 Less than 55 68 Less than 65 82 Less than 75 92 Less than 85 100 Less than 95 105 Soln:- 49.46 Following is the distribution of marks obtained by 50 students in marketing. Calculate median. No. of Marks More than students 0 50 10 46 20 40 30 20 40 10 50 3 Soln:- 153.79 By using the median found out the missing frequencies. It is given that median is 43.6 and total of frequency is 132. Class 0-10 10-20 20-30 30-40 40-50 50-60 60-7o 70-80 80-90 Intervals Frequency 10 12 15 ? 25 ? 12 11 9 Soln:- 43.6 Page 4 23. Calculate the value of the median quartile one and quartile three from the following. Values Frequency Values Frequency 4-6 2 18-20 10 6-8 5 20-22 7 8-10 4 22-24 6 10-12 11 24-26 4 12-14 11 26-28 3 14-16 11 28-30 1 16-18 13 Soln:- Q1=12, Q3=19.8 MODE 24. Locate mode of the data by grouping method. X 0.5 1.5 2.5 3.5 4.5 5.5 F 6 11 12 19 22 18 25. Calculate mode of following data. Marks 0-9 10-19 20-29 Student 2 10 18 30-39 20 40-49 38 6.5 10 50-59 25 7.5 22 8.5 3 9.5 2 10.5 11.5 1 1 Soln:- 4.5 60-69 16 70-79 10 80-89 90-99 8 3 Soln:- 45.31 250300 19 300350400350 400 450 10 3 3 Soln:- 204.84 26. Calculate the mode from the following series. Size of item Frequency 0-5 20 5-10 24 10-15 32 15-20 28 20-25 20 25-30 16 30-35 34 35-40 10 40-45 8 Soln:- 13.33 27. Calculate Mode of the following information. Class 1001500-50 50-100 Interval 150 200 Frequency 2 2 18 22 200250 21 28. Calculate the modal value from the following. Income Rs. No. of Persons Less than 100 8 Less than 200 22 Less than 300 35 Less than 400 50 Less than 500 57 Less than 600 60 Soln:- 257.96 29. Find out the mode from the following table with which profits are made Profits Rs. 3-4 4-5 5-6 6-7 7-8 Frequency 83 27 25 50 75 DMIMS 8-9 38 9-10 18 Soln:- 7.40 Page 5 Range 30. Find the range of weight of 10 students from the following. 41 11 14 65 73 64 53 31. Calculate the range and semi-inter quartile range for wages. Wages Rs. 30-32 32-34 34-36 36-38 Labourers 12 18 16 14 32. Compute range and its Co-efficient for the following data. Classes 10-20 20-30 30-40 40-50 50-60 Frequency 12 15 16 16 25 35 71 55 Soln:- Range=62, Coeff of range=0.738 38-40 12 40-42 8 60-70 30 70-80 25 42-44 6 Soln:- Rs.14 80-90 90-100 10 8 Soln:- 0.82 QUARTILE DEVIATION 33. Compute quartile deviation and its co-efficient for the following data. X 110 111 112 113 114 115 116 117 118 119 120 121 Soln:- 0.028 34. Compute quartile deviation and co-efficient of quartile deviation for the given information. X 10 12 14 16 18 20 22 24 28 30 34 36 38 F 3 6 10 15 20 24 30 22 18 14 10 6 6 Soln:- 0.22 35. The following are the marks of 115 students. Calculate co-efficient of quartile deviation. Marks Below Below Below Below Below Below Below Below Below 10 20 30 40 50 60 70 80 90 Students 2 10 12 42 67 88 102 108 112 Soln:36. Compute Mean Deviation and Co-efficient of mean deviation for A series & B series. A 105 112 110 125 138 149 161 175 185 B 22 24 26 28 30 32 34 40 44 37. Calculate Mean Deviation of the following data. X 12 14 16 F 2 2 3 18 2 22 1 Below 100 115 0.28 190 50 Soln:- 0.128 24 1 Soln:- 0.16 MEAN DEVIATION 38. Calculate mean deviation from the following data X 2 4 F 1 4 6 6 8 4 10 1 Soln:- 1.5 39. Calculate mean deviation from median of mark obtained from the following data. 8,20,15,17,2,10,30,38,28,39,4,8,6,12,18,18,29,37,23,18,16,15,24,14,28,27,35,49,9,13,6,18,22,25,30 Soln:- 9.114 40. Calculate mean deviation for the following frequency distribution. No. of colds experienced 0 1 2 3 4 5 6 7 8 9 in 12 months f 25 46 91 162 110 95 82 26 13 2 Soln:- 1.5 DMIMS Page 6 41. With median as the base calculate the mean deviation of the two series A and B Series A Series B 3484 487 4572 508 4124 620 3682 382 5624 408 4388 266 3680 186 4308 218 Soln:- A=490.25, B=121.38 42. Calculate mean deviation from median from the following Marks Less than No. of Students 80 100 70 90 60 80 50 60 40 32 30 20 20 13 10 5 Soln:- 14.28 43. Calculate mean deviation and coefficient of mean deviation from the following data. Class Interval f 20-25 6 25-30 12 30-40 17 40-45 30 45-50 10 20-25 6 50-55 10 55-60 8 60-70 5 70-80 2 Soln:- M.D=8.75, Co. M.D=0.206 44. Calculate mean deviation from mean from the following Size of item Frequency 3-4 3 4-5 7 5-6 22 6-7 60 7-8 85 8-9 32 9-10 8 Soln:- 0.915 DMIMS Page 7 STANDARD DEVIATION 45. Calculate the Standard Deviation and its Co-efficient for the following data. S.N 1 2 3 4 5 6 7 8 9 X 30 50 60 70 90 100 105 120 125 46. Calculate standard deviation of the following data. S.N. 1 2 3 4 5 X 40 42 38 56 15 6 71 7 82 10 11 12 130 150 170 Soln:- 40.16% 8 9 65 37 Soln:- 23.74 10 80 47. Calculate Standard Deviation and its Co-efficient for the sales in a year by 100 salesmen. Sales 50 100 150 200 250 300 350 (Rs. 000) Salesmen 4 14 22 30 20 8 2 Soln:- 35.3% 48. The following data is about the expenditure of 100 units in a firm. Compute standard deviation and Coefficient. Expenses 20-30 30-40 40-50 50-60 60-70 70-80 80-90 90100110100 110 120 Units 4 10 11 12 18 15 10 8 8 4 Soln:- 23.6 49. The following are the share prices of five industries in ten months. Compute standard deviation and find out the industry whose prices are more consistent and which company is more variable. Months Share Prices (Rs.) A B C D E Jan 26 75 150 150 200 Feb 28 77 120 155 210 Mar 29 80 110 160 220 Apr 35 82 125 165 230 May 30 84 145 170 240 Jun 29 82 172 175 250 July 36 80 175 180 260 Aug 48 85 182 185 270 Sept 53 88 195 190 280 Oct 76 97 196 200 290 Soln:- A 50. By using the following data calculate co-efficient of X & Y. Particulars X Y Variance 25 16 Average 150 85 Soln:- 4.71 DMIMS Page 8 UNIT II - REGRESSION ANALYSIS Regression Equation 1. By using the following information obtain two regression equations. X 2 4 8 6 7 9 Y 5 4 9 8 9 7 Soln: x= -0.37+0.191y, y= -59+11x 2. From the data given below calculate the regression equation by taking deviations from the mean of X & Y series and estimate Y when X is 12 and estimate X when Y is 14. X 2 3 4 5 6 7 8 Y 4 6 8 9 12 15 16 Soln: X= 0.3+0.47Y, Y=0.35+2.07X 3. Find the two regression lines by using the following data and estimate Y when X is, 9, 10 &12. X 15 18 26 28 31 25 19 35 Y 10 11 16 19 17 14 11 24 Soln: Y= 6.94, 7.6, 8.92 4. Calculate two regression equations by using Karl Pearson’s coefficient of correlation and standard deviations for the given information. X 2 4 6 7 8 10 12 Y 16 15 18 19 17 21 20 Soln: X= -16.94+1.33Y, Y=14.29+0.53X 5. Calculate two regression equations by using Karl Pearson’s coefficient of correlation and standard deviations for sales and profits as given below. Estimate profits when sales increase to Rs.42 Lakhs and Rs.45 Lakhs. Sales in Rs. 5 10 15 20 25 30 35 Lakhs X Profits in 6 8 12 14 16 18 20 Rs.”000” Y Soln: X=0.32+1.64Y, Y=6.8+0.26X 6. Determine the regression of Y on X and X on Y for the following data by using normal equation method. X 5 8 7 6 4 Y 3 4 5 2 1 Soln: Y= -1.8+0.8x, X=3.6+0.8y 7. From the following data obtain two regression equations by using normal equations. X 6 2 10 4 8 Y 9 11 5 8 7 Soln: Y=11.9-0.65x, X=16.4-1.3y 8. Obtain two regression equations X on Y and Y on X for the following data. X 7 8 11 5 3 1 15 Y 18 20 35 20 15 12 45 Soln: Y=6.6+2.4x, X=1.8+0.38y 9. Determine regression equation Y on X for the information given below and estimate Y when X=100, 105, 110 and 115. DMIMS Page 9 X Y 50 3.5 80 7.0 60 5.0 70 6.0 90 5.0 60 4.0 80 6.0 50 70 90 4.0 5.5 4.0 Soln: Y=2.55+0.03x 10. By using the following information obtain regression equation Y on X on Y. X Y A.M 22.5 18.8 Standard Deviation 2.87 1.4 Co-efficient of Correlation 0.97 Soln: X=1.99y-14.9, Y=8.2+0.47x 11. By using the following information obtain regression equation Y on X. and X on Y. X Y A.M 5 12 Standard Deviation 2.6 2.6 Co-efficient of Correlation 0.95 Soln: X= -6.4+0.95y, Y= 7.25+0.95x 12. Construct regress equation for the information given below. X 23 43 53 63 73 83 Y 5 6 7 8 9 10 Soln: Y=26.73+0.56x, X= -29.38+11.43y 13. From the data given below find the regression equations X 1 5 3 2 1 1 7 3 y 6 1 0 0 1 2 1 5 (i) Estimate y, when x= 10 (ii) Estimate x, when y=13 Soln:- Y= -0.304x+2.874, X=0.278y+3.431, Y= -0.13, X= 2.62 14. Calculate the two regression equations from the data given below, Price (Rs.) 10 12 13 12 16 15 Demand(Units) 40 38 43 45 37 43 Soln:- Y= -0.25x+44.25, X=-0.12y+17.92 15. The following table shows number of motor registrations in a certain territory for a term of 5 years and the sale of motor tyres by a firm in that territory for same period. Year Motor registrations No.pf tyres sold 1 600 1250 2 630 1100 3 720 1300 4 750 1350 5 800 1500 Find the regression equation to estimate the sale of tyres when motor registration is known. Estimate sales of tyres when registration is 850. Soln:- Y=1.493X++254.9; Y=15.24 16. The heights of a group of fathers and sons are given below. Height of 158 160 163 165 167 170 father Height of 163 158 167 170 160 180 Son DMIMS 172 175 177 181 170 175 172 175 Page 10 Find the lines of regression and estimate the height of the son when the height of the father is 164 cm. Soln:- X=0.76Y-40.36; Y=0.71X+49.15; Y=165.59 17. The following data give the monthly income and expenditure on food of 10 families. Income 120 90 80 150 130 140 110 95 70 105 Expenditure 40 36 40 45 40 44 45 38 50 35 Calculate regression of food on income Soln:- Y=0.011X+40.101 18. By using karl pearsons find out; (a) Regression equation of Y on X (b) Regression equation of X on Y (c) Most probable value of Y, when X is 10 X 1 2 3 4 5 Y 2 5 3 8 7 Soln:- (a) Y=1.1+1.3X; (b) X=0.5+0.5Y; (c) Y=14.1 19. You are given the data of purchase and sales. Obtain two regression equations by least square and estimate the likely sales when purchase equal to 100. Purchase 62 72 98 76 81 56 76 92 88 49 Sales 112 124 131 117 132 96 120 136 97 85 Soln:- X=0.65Y+0.25; Y=0.78X+56.5; Expected sales=134.5 20. Use the following data; X 1 5 3 2 1 1 7 Y 6 1 0 0 1 2 1 (a) Fit a regression line of Y on X and hence predict X if Y=25 (b) Fit a regression line of X on Y and hence predict Y if X=5 (c) Calculate Karl Pearson’s correlation coefficient Soln:- (a) Y= -0.304X+2.874; Y=1.354 (b) X= -0.287Y+3.431; X=2.736 (c) y= 0.291 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. DMIMS 3 5 Define the term Regression and explain its features and objectives. What is regression analysis? How does it differ from correlation analysis? What is regression? Explain different types of regression with examples. Explain the concept of regression. How do you measure regression? What is regression Line? Explain its uses. State any two merits of the method of the Least Square. What is the utility of regression? What do you mean by Regression Coefficient? What are the properties of Regression Coefficient? “Y=a+bx” where it is used? Page 11 UNIT III - CORRELATION ANALYSIS 1. Calculate the coefficient of correlation between x & y from the following data; X 1 2 3 4 5 6 Y 2 4 5 3 8 6 7 7 Soln:-ᵞ =0.79 2. Calculate Karl Pearson’s coefficient of correlation. X 2 4 6 Y 12 14 16 8 18 10 20 Soln:-ᵞ=1 3. Calculate Karl Pearson’s coefficient of correlation. X 2 4 6 Y 20 18 16 8 14 10 12 Soln:-ᵞ=-1 4. From the following table calculate the coefficient of correlation by Karl Pearson’s. X 6 2 10 4 8 Y 9 11 ? 8 7 Arithmetic mean of X & Y are 6 & 8 respectively. Soln:- r=-0.92 5. Find the coefficient of correlation between the sales and expenses of the following 10 firms; Firm 1 2 3 4 5 6 7 8 9 10 Sales 50 50 55 60 65 65 65 60 60 50 Expense 11 13 14 16 16 15 15 14 13 13 Soln:- ᵞ= 0.7866 6. Calculate pearson’s coefficient f correlation from the following taking 100 and 50 as the assumed averages of X & Y respectively X 104 111 104 104 118 117 105 108 106 100 104 105 Y 57 55 47 45 45 50 64 63 66 62 69 61 Soln:- ᵞ=-0.674 7. The index numbers of prices of all commodities in Bombay and in Calcutta were as; Month Price in Calcutta Price in Bombay Jan 169 204 Feb 182 222 Mar 182 225 Pr 192 228 May 198 229 Jun 209 233 Jul 227 249 Aug 238 266 Sept 250 255 Oct 253 255 Calculate the coefficient of correlation between prices in Calcutta & Bombay. Soln:- ᵞ= 0.943 DMIMS Page 12 8. Calculate the coefficient of correlation between age of cars and annual maintenance cost and comment; Age of car Maintenance cost 2 16 4 15 6 18 7 19 8 17 10 21 12 20 Soln:- ᵞ= 0.8357 9. The following are the result of an examination; Age of Candidates Successful candidates appeared candidates 13-14 200 124 14-15 300 180 15-16 100 65 16-17 50 34 17-18 150 99 18-19 400 252 19-20 250 145 20-21 150 81 21-22 25 12 22-23 75 33 Calculate coefficient of correlation between age and successful candidates. Soln:- ᵞ=-0.77 10. The following table gives the distribution of the total population and those who are totally and partially blind among them. Find is any relation in age & blindness. Age 0-10 10-20 20-30 30-40 40-50 50-60 60-70 70-80 No of 100 60 40 36 24 11 6 3 person Blind 55 40 40 40 36 22 18 15 Soln:- ᵞ= 0.898 11. The following table gives the frequency according to age groups of marks obtained by 67 students in an intelligence test; Test Marks Age in years 18 19 20 21 Total 200-250 4 4 2 1 11 250-300 3 5 4 2 14 300-350 2 6 8 5 21 350-400 1 4 6 10 21 Is there any relationship between age and intelligence? Soln:- ᵞ=0.4151 12. The following table gives the distribution of the ages in years of husband and wives in 100 couples Age of wives Age of husbands 20-25 25-30 30-35 35-40 15-20 20 10 3 2 20-25 4 28 6 4 25-30 5 11 30-35 2 35-40 5 Calculate coeff of correlation between age of husbands & wives. DMIMS Page 13 Soln:- ᵞ=0.61 13. Compute the correlation coefficient and the probable error for the following data; Sales Revenue Advertising Expenditure (Rs. ‘000) (Rs. ‘000) 5-15 15-25 25-35 35-45 Total 75-125 4 1 5 125-175 7 6 2 1 16 175-225 1 3 4 2 10 225-275 1 1 3 4 9 Total 13 11 9 7 40 Soln:- ᵞ=0.596 14. Find the ceff. Of correlation between marks obtained by 60 candidates in economics & statistics from the data given below; Marks in Marks in economics statistics 5-15 15-25 25-35 35-45 0-10 1 1 10-20 3 6 5 1 20-30 1 8 9 2 30-40 3 9 3 40-50 4 4 Soln:- ᵞ=0.533 15. The following are the marks obtained by the students in Statistics and Law R.No. Marks R.No. Marks Statistic Law Statistic Law 1 15 13 13 14 11 2 0 1 14 9 3 3 1 2 15 8 5 4 3 7 16 13 4 5 16 8 17 10 10 6 2 9 18 13 11 7 18 12 19 11 14 8 5 9 20 11 7 9 4 17 21 12 18 10 17 16 22 18 15 11 6 6 23 9 15 12 19 18 24 7 3 Prepare a correlation table taking the magnitude of each class interval as 4 marks and class interval as equal to 0 and less than 4. Calculate Karl Pearson’s coeff. of correlation between marks in stat and law. Soln:- ᵞ=0.578 16. A survey of incomes & expenses on food of 100 teachers is shown; Food Exp. Family Income (Rs.) (in %) 200-300 300-400 400-500 500-600 10-15 3 15-20 4 9 4 20-25 7 6 12 5 25-30 3 10 19 8 Calculate coeff. of correlation and interpret its value. DMIMS 600-700 7 3 - Page 14 Soln:- ᵞ=-0.4381 Rank Correlation 17. Two judges in a beauty competition rank the 12 entries as follows X 1 2 3 4 5 6 7 8 9 10 Y 12 9 6 10 3 5 4 7 8 2 11 11 12 1 Soln:- ᵞs=-0.4545 18. Calculate Spearman’s rank correlation between advertisement cost and sales; Advt. Cost 39 65 62 90 82 75 25 98 36 78 (Rs.’000) Sales 47 53 58 86 62 68 60 91 51 84 (Rs.’00,000) Soln:- ᵞs=0.82 19. Following are the scores of 10 students in a class and their I.Q. Student Scores I.Q. 1 35 100 2 40 100 3 25 110 4 55 140 5 85 150 6 90 130 7 65 100 8 55 120 9 45 140 10 50 110 Soln:- ᵞs=0.47 20. Ten competitors in a beauty contest are ranked by three judge in following order 1st Judge 1 5 4 8 9 6 10 7 3 2 2nd Judge 4 8 7 6 5 9 10 3 2 1 rd 3 Judge 6 7 8 1 5 10 9 2 3 4 Use rank correlation coefficient to discuss which pair of judges has nearest approach to common liking. Soln:-I & II ᵞs=-0.212; II & III ᵞs=0.297; I & III ᵞs=0.636; 21. What is meant by correlation? What are the properties of coefficient of correlation? 22. Distinguish between coefficient of correlation and coefficient of variation. 23. Define Karl Pearson’s coefficient of correlation. What is intended to measure? 24. Distinguish between (a) Positive & Negative Correlation (b)Linear & Non Linear Correlation (c)Simple, Partial and Multiple Correlation 25. Define coefficient of correlation and mention its important properties. 26. What are the methods of calculating coefficient of correlation? DMIMS Page 15