Mean for Ungrouped Data

Q.

What is the ratio of the sum of all observations to the number of observations called?

__

Q.

Krishna’s family has 4 members. The daily rice consumption of the 4 family members is - 0.5 kg, 0.4 kg, 0.3 kg and 0.6 kg. Krishna wants to find the average rice consumption per family member. What is the measure that will come into use now?

1. Median

2. Mean

3. Mode

4. Median or Mode

Q.

The mean $\overline{x}$ of a grouped data is given by:

1. $\frac{\sum f_i{x}_i}{\sum f_i}$

2. $\frac{\sum f_i}{x_i}$

3. $\frac{\sum x_i}{f_i}$

4. $\frac{\sum f_i{x}_i}{\sum x.f}$

Q. There are _______ methods to find the mean value for a grouped data.

1. two
2. three
3. four
4. five

Q.

The value of ${\sum }_{i=1}^n{x}_i$ is

1. $\frac{\overline{X}}{2}$

2. $\frac{\overline{X}}{n}$

3. $2\overline{X}$

4. $n\overline{X}$

Q.

The arithmetic mean of 1, 2, 3, 4, 5, ……., n is ____.

1. $\frac{n+1}{2}$

2. $\frac{n-1}{2}$

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

4. $\frac{n}{2}+1$

Q.

$\sum$fx = 5x + 2, $\sum$f = 12. If the mean of the distribution is 6, what is the value of x?

1. 12

2. 14

3. 15

4. 18

Q.

The mean calculated for the raw data will have the exact same value as that of the corresponding grouped data.

1. True

2. False

Q.

The average weight of a group of 25 men was calculated to be 78.4 kg. It was discovered later that one weight was wrongly entered as 69 kg instead of 96 kg. What is the correct average ?

1. 80.30

2. 79.48

3. 77.56

4. 75.76

Q. The three methods to find the mean from the grouped frequency distribution are _______.

1. Assumed method, Direct mean method and Step deviation method
2. Direct method, Assumed mean method and Step deviation method
3. Grouped method, Ungrouped method and Step deviation method.
4. Grouped method, Ungrouped method and Direct method.