Statistics Test...

Which of the following is not the measure of dispersion.

Coefficient of quartile deviation of numbers $$6, 8, 9, 10, 11, 12, 14$$ is?

The average marks of $$10$$ students in a class was $$60$$ with standard deviation $$4$$. While the average marks of other $$10$$ students was $$40$$ with a standard deviation $$6$$. If all the $$20$$ students are taken together, their standard deviation will be.

Find the coefficient of range for the data $$43,24,38,56,22,39,45$$

If $$b_{i} = 1 - a_{i}, na = \displaystyle \sum_{i = 1}^{n} a_{i}, nb = \displaystyle \sum_{i = 1}^{n}b$$, then $$\displaystyle \sum_{i = 1}^{n}a_{i}b_{i} + \displaystyle \sum_{i = 1}^{n} (a_{i} - a)^{2} =$$

The following are the wages of 8 workers in a factory. Find the range and coefficient of range. Wages are in dollars: 1400, 1450, 1520, 1380, 1485, 1495, 1575, 1440.

Find the coefficient of range for the given data
$$59,46,30,23,27,40,52,35,29$$

Which of the following is correct about measure of dispersion?

If the coefficient of range is $$0.18$$ and the largest value is $$7.44$$,then the smallest value is?

The weight in Kg of 13 students in a class are $$42.5,47.5,48.6,50.5,49,46.2,49.8,45.8,43.2,48,44.7,46.9,42.4$$.Find the coefficient of range.