# Standard Deviation about Mean for Continuous Frequency Distributions

## Trending Questions

**Q.**The variance of first 20 natural numbers is

- 133/4
- 399/4
- 133/2
- 279/12

**Q.**

The binomial distribution for which mean = 6 and variance = 2, is

**Q.**If the sum and the product of mean and variance of a binomial distribution are 24 and 128 respectively, then the probability of one or two successes is:

**Q.**

What is the meaning of the term deviation?

**Q.**

The G.M of the numbers $3,{3}^{2},{3}^{3},.....{3}^{n}$ is

${3}^{\frac{2}{n}}$

${3}^{\frac{n+1}{2}}$

${3}^{\frac{n}{2}}$

${3}^{\frac{n-1}{2}}$

**Q.**In binomial probability distribution, mean is 3 and standard deviation 32is

**Q.**In an experiment there are 20 observation for which following results are given

∑x2=8100, ∑x=214

One observation that was 42 was found to be wrong and it was replaced by the correct value 28. Then the corrected standard deviation is

- 15.8
- 16
- 12
- 21.35

**Q.**

If a be the arithmetic mean of b and c and G1, G2 be the two geometric means between them, then G31+G32=

- abc
- 2abc
- None of these
- 3abc

**Q.**

A box contains $15$ green and $10$ yellow balls. If $10$ balls are randomly drawn, one-by-one, with replacement, then the variance of the number of green balls drawn is

$\frac{12}{5}$

$\frac{6}{25}$

$6$

4

**Q.**

Suppose, X has a binomial distribution B(6, 12). Show that X=3 is the most likely outcome.

**Q.**

How do you find the arithmetic mean of grouped data $?$

**Q.**Two subsets A and B of a set ‘S’ consisting of ‘n’ elements are constructed randomly. The Probability that A⊑B is equal to:

- 12n
- (34)n
- 2nn!
- (23)n

**Q.**Mean and Standard Deviation of 100 items are 50 and 4 respectively. The sum of all squares of the items is...

- 266000
- 251600
- 261600
- 256100

**Q.**

The mean deviation from the mean of the set of observations $-1,0,4$ is

$3$

$1$

$-2$

$2$

**Q.**

If the mean deviation of number $1,1+d,1+2d....,1+100d$from their mean is $255$, then $d$ is equal to

$10.0$

$20.0$

$10.1$

$20.2$

**Q.**Which of the following is not a measure of central location?

- Mean
- Median
- Mode
- Variance

**Q.**

Define the term variance.

**Q.**A sample space consists of integers 1, 2, 3, ....100. The probability of choosing an integer k is proportional to lnk. The conditional probability of choosing the integer ′2′, given that an even integer is chosen is

- ln250ln2+ln50!
- ln2ln2+ln50!
- ln250ln2+ln50
- ln2ln2+ln50

**Q.**The mean and variance of a random variable X having a binomial distribution are 6 and 3 respectively. The probability of variable X less than 2 is

- 132048
- 134096
- 252048
- 154096

**Q.**The mean and the variance of a binomial distribution are 4 and 2 respectively. Then the probability of 2 successes is

- 37256
- 28256
- 128256
- 129256

**Q.**

In a meeting, 70% of the members favour a certain proposal, 30% being opposite. A member is selceted at random and let X=0, if he opposed and X=1, if he is in favour. Find E(X) and V(X)

**Q.**A die is thrown 6 times. If ‘getting an odd number’ is a success, then the probability of 4 successes is

- 1564
- 14
- 3564
- 1364

**Q.**The coefficient of variance is 60 and standard deviation is 24, then Arithmatic mean is

- 40
- 720
- 207
- 140

**Q.**In binomial distribution, the sum and the product of mean and the variance are 253 and 503 respectively. Determine the distribution.

**Q.**The mean and variance of a random variable X having a binomial distribution are 6 and 3 respectively. Find the probability of variable X less than 2.

**Q.**Consider the following statements:

1. Variance is unaffected by change of origin and change of scale.

2. Coefficient of variance is independent of the unit of observations.

Which of the statements given above is/ are correct?

- Both 1 and 2
- 1 only
- Neither 1 nor 2
- 2 only

**Q.**Calculate the variance and standard deviation of the following continuous frequency distribution

Class interval | 30−40 | 40−50 | 50−60 | 60−70 | 70−80 | 80−90 | 90−100 |

Frequency | 3 | 7 | 12 | 15 | 8 | 3 | 2 |

**Q.**If the median of the data 6, 7, x−2, x, 18, 21 written in ascending order is 16, then the variance of the data is

- 3015
- 3113
- 3212
- 3313

**Q.**The variance of the data 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 is

- 15
- 20
- 30
- 33

**Q.**The variance of first 30 natural numbers, is

- 74.92
- 38.98
- none of these
- 37.98