# Maths Statistics Practice Questions Essay

If the arithmetic mean of 7,9,11,13, x, 21 is 13,find the value of x. 2. The mean of 24 numbers is 35. If 3 is added to each number, what will be new mean.? 3. The mean of 20 numbers is 43. If 6 is substracted from each of the numbers,what will be new mean? 4. The mean of 15 numbers is 27. If each numbers is multiplied by 4,what will be new mean? 5. The mean weight of 6 boys in a group is 48 kg. The individual weights of five of them are 51kg, 45kg, 49kg, 46kg, and 44kg. Find the weight of the sixth boy. . The mean of the marks scored by 50 students was found to be 39. Later on it was found that a score of 43 was misread as 23. Find the correct mean. 7. The mean of 100 items was found to be 64. Later on it was found that two of the items were misread as26 and 9 instead of 36 and 90 respectively. Find the correct mean. 8. A cricketer has a mean score of 58 runs in 9 innings. Find out how many runs are to be scored by him in the tenth innings to raise the mean score to 61. 9. The mean of 25 observations is 36.

If the mean of the first 13 observations is 32 and that of the last 13 observations is 39, find the 13th observation. 10. A batsman in his 12th innings makes a score of 63 runs and thereby increase his average score by 2, what is his average after the 12th innings ? 11. The mean of 31 observations is 60. If the mean of the first 16 observations is 58 and that of the last 16 observations is 62, find the 16th observation. 12. The heights of 72 plants in a garden are given below : Heights(in cm)| 58| 60| 62| 64| 66| 68|

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No. of plants| 12| 14| 20| 13| 8| 5| Find the mean height per plant. 13. The mean of the following data is 21. 6. find the value of p. X| 6| 12| 18| 24| 30| 36| F| 5| 4| p| 6| 4| 6| | 14. The mean of the following data is 1. 46. find the value of missing frequencies. No of accidents(x)| 0| 1| 2| 3| 4| 5| Total| No of drivers(f)| 46| ? | ? | 25| 10| 5| 200| 15. If 10,13,15,18, x+1, x +3, 30 ,32, 35, 41are ten observations in an ascending order with median 24, find the value of x.