Question: From the following data, find the standard deviation and coefficient of variation. Class Interval 20-30 30-40 40-50 50-60 60-70 70-80 Frequency 10 15 25 30 12 …

Question: From the following data, find the standard deviation and coefficient of variation. Class Interval 0-10 0-20 0-30 0-40 0-50 Frequency 8 18 30 38 40 Solution: Using actual mean, [ We have, interval between two classes is 10. To get the frequency, subtract the give frequency of the respective class from one step higher class.…

Question: Find the standard deviation: Class Interval 0-10 0-20 0-30 0-40 0-50 Frequency 2 5 10 13 15 Solution: [Comment: assumed mean is easier way to perform standard deviation, so we use Assumed Mean method] Taking Assumed Mean (A) = 25 Arranging the given data in a table; X f Mid-value (m) d(x-25) d² fd fd² 0-10 2 5 -20 400 -40 …

Question: Find the standard deviation of the following data: Wage (in RS.) 60-62 63-65 66-68 69-71 72-74 No. Of Workers 5 18 42 27 8 Solution: Using assumed mean method [ In this method, the mean is taken as the mid-value of the mid-class from the given data. Here, mid term is mid-class is 66-68 and the mid-value is 67 ] Taking Assu…

Question: Find the standard deviation using actual mean. X 0-10 10-20 20-30 30-40 40-50 50-60 f 4 6 10 20 6 4 Solution: Using actual mean, Arranging the data in a table, X f m fm d|x-31| d² fd² 0-10 4 5 20 26 676 2704 10-20 6 15 90 16 256 1536 20-30 10 25 250 -6 36 360 30-40 20 35 700 4 16 …

Question: Find the standard deviation of the following data: Class Interval 0-10 10-20 20-30 30-40 40-50 Frequency 5 15 25 35 45 Solution: Taking Assumed Mean (A) = 25 Arranging the given data in a table; Marks Frequency (f) Mid-value (m) d(x-25) d² fd fd² 0-10 5 5 -20 400 -100 2000 10-20 15 15 -10 100 -150 1500 20-30 25 25 0 0 0 0 …

Question: Find the standard deviation of the following data: Class Interval 25-35 35-45 45-55 55-65 65-75 Frequency 5 4 6 7 3 Solution: [Comment: assumed mean is easier way to perform standard deviation, so we use Assumed Mean method] Taking Assumed Mean (A) = 50 Arranging the given data in a table; Marks Frequency (f) Mid-value (m)…

Question: Find the standard deviation of the following data: Class Interval 0-10 10-20 20-30 30-40 40-50 Frequency 5 8 15 16 6 Solution: [Comment: assumed mean is easier way to perform standard deviation, so we use Assumed Mean method] Taking Assumed Mean (A) = 25 Arranging the given data in a table; Marks Frequency …