The number of telephone calls received at an exchange in 245 successive one-minute intervals are shown in the following frequency distribution: Number of calls 0 1 2 3 4 5 6 7 Frequency 14 21 25 43 51 40 39 12

The number of telephone calls received at an exchange per interval for 250 successive one-minute intervals are given in the following frequency table: No. of calls (x) : 9 1 2 3 4 5 6 No. of intervals (f) : 15 24 29 46 54 43 39 Compute the mean number of calls per interval.

Find the mean of the following frequency distributions: Class interval: 25-35 35-45 45-55 55-65 65-75 Frequency: 6 10 8 12 4

Find the mean of the following frequency distributions: Class interval: 0-10 10-20 20-30 30-40 40-50 Frequency: 9 12 15 10 14

Find the mean of the following frequency distributions: Class interval: 0-8 8-16 16-24 24-32 32-40 Frequency: 6 7 10 8 9

Calculate mean, variance and standard deviation of the following frequency distribution: Class 1-10 10-20 20-30 30-40 40-50 0-60 Frequency: 11 29 18 4 5 3

Find the mean of the following frequency distributions: Class interval: 0-6 6-12 12-18 18-24 24-30 Frequency: 7 5 10 12 6

The median class in the following frequency distribution is {:("Class interval :",0-10,10-20,20-30,30-40,40-50),("Frequency :",12,13,25,20,10):}

Find The standard deviation of the following frequency distribution is {:(X,2,3,4,5,6,7),(f,4,9,16,14,11,6):}

Find the mean of the following frequency distributions: Class interval: 0-6 6-12 12-18 18-24 24-30 Frequency: 6 8 10 9 7

Find the mean of the following frequency distributions: Class i n t erval: 0-8 8-16 16-24 24-32 32-40 Frequency: 5 6 4 3 2