Advertisements
Advertisements
Question
Find the Standard Deviation of the following data: 14, 22, 9, 15, 20, 17, 12, 11.
Advertisements
Solution
σ = `sqrt(((sum(x - barx)^2)/"n"))`
= `sqrt(426/9)`
= `sqrt(47.33)`
∴ σ = 4.18
APPEARS IN
RELATED QUESTIONS
Find variance and S.D. for the following set of numbers:
65, 77, 81, 98, 100, 80, 129
Compute variance and standard deviation for the following data:
| X | 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 |
| F | 8 | 10 | 10 | 7 | 6 | 4 | 3 | 4 | 2 | 6 |
Following data gives age of 100 students in a college. Calculate variance and S.D.
| Age (In years) | 16 | 17 | 18 | 19 | 20 | 21 |
| No. of Students | 20 | 7 | 11 | 17 | 30 | 15 |
Find mean, variance and S.D. of the following data:
| Classes | 10 – 20 | 20 – 30 | 30 – 40 | 40 – 50 | 50 – 60 | 60 – 70 | 70 – 80 | 80 – 90 | 90 – 100 |
| Frequency | 7 | 14 | 6 | 13 | 9 | 15 | 11 | 10 | 15 |
Find the variance and S.D. of the following frequency distribution which gives the distribution of 200 plants according to their height:
| Height (in cm) | 14 – 18 | 19 – 23 | 24 – 28 | 29 – 33 | 34 – 38 | 39 – 43 | 44 – 48 |
| No. of plants | 5 | 18 | 44 | 70 | 36 | 22 | 5 |
Select the correct option from the given alternatives :
The standard deviation of a distribution divided by the mean of the distribution and expressing in percentage is called:
Select the correct option from the given alternatives :
The positive square root of the mean of the squares of the deviations of observations from their mean is called:
Select the correct option from the given alternatives :
For any two numbers, SD is always
Answer the following :
Find variance and S.D. for the following set of numbers: 125, 130, 150, 165, 190, 195, 210, 230, 245, 260
Answer the following :
Given below is the frequency distribution of marks obtained by 100 students. Compute arithmetic mean and S.D.
| Marks | 40 - 49 | 50 - 59 | 60 - 69 | 70 - 79 | 80 - 89 | 90 - 99 |
| No. of students | 4 | 12 | 25 | 28 | 26 | 5 |
The mean and standard deviation of random variable X are 10 and 5 respectively, then `"E"(("X" - 15)/5)^2` = ______.
Consider three observations a, band c such that b = a + c. If the standard deviation of a + 2, b + 2, c + 2 is d, then which of the following is true?
The mean and standard deviation of 20 observations were calculated as 10 and 2.5 respectively. It was found that by mistake one data value was taken as 25 instead of 35. If α and `sqrtβ` are the mean and standard deviation respectively for correct data, then (α, β) is ______.
If the mean of the data 7, 7, 9, 7, 8, 7, λ, 8 is 7, then the variance of this data is ______.
The mean of a data set consisting of 20 observations is 40. If one observation 53 was wrongly recorded as 33, then the correct mean will be ______.
The mean and variance of 10 observations were calculated as 15 and 15 respectively by a student who took by mistake 25 instead of 15 for one observation. Then, the correct standard deviation is ______.
The mean and standard deviation of 50 observations are 15 and 2 respectively. It was found that one incorrect observation was taken such that the sum of correct and incorrect observations is 70. If the correct mean is 16, then the correct variance is equal to ______.
