In the following frequency distribution if the arithmetic mean is 45.6. Find out the missing frequency.

Wage	No. of Workers
10-20 20-30 30-40 40-50 50-60 60-70 70-80	5 6 7 ? 4 3 9

Which average is affect most by the presence of extreme items?

The algebraic sun of deviation of a set of n values from A.M. is =:

Comment on whether the following statements are True or False.

Following information pertains to the daily income of 150 families. Calculate the arithmetic means.

If the arithmetic mean of the data given below is 28, find (a) the missing frequency and (b) the median of the series.

The following series relates to the daily income of workers employed in a firm. Compute the (a) highest income of lowest 50% workers, (6) minimum income earned by the top 25% and (c) maximum income earned by lowest 25% workers.

The following table gives production yield in kg. per hectare of wheat of 150 arms in a village. Calculate the mean, median and mode production yield.

The size of land holdings of 380 families in a village is given below. Find the median size of land holdings.

What do you mean by 'Average'?

Pocket expenditures of 6 students are (Rs.) 6,12,18,24,30 and 36 respectively. Find out arithmetic mean.