Find the mean height of 65 boys from the following data :
`{:("Height (in cm)",142,144,146,148,150,152),("Number of boys",10,13,12,7,17,6):}`

Find the mean weight of 50 boys from the following data : {:("Weight (in kg)",50,52,54,56,60),("Number of boys (frequency)",6,8,15,14,7):}

Find the mean weight of 40 boys from the following data : {:("Weight (in kg)",27,28,29,30,31),("Number of boys",6,12,10,8,4),("(Frequency)",,,,,):}

The following table shows the heights of 50 students of a class : {:("Height (in cm)",152,148,150,153,149,151,147),("Number of students",8,3,4,7,12,10,6):} Find the mean and the median. Using empirical formula, calculate its mode.

Find the 20^(th) percentile of the following data : {:("Height (in cm)",135,140,145,150,155,160,165,170),("No. of students",7,20,32,48,36,28,24,4):}

Find the mean deviation about the mean for the following data: 6, 7, 10 , 12 , 13 , 4, 8, 12

The heights (in cm) of 35 students of a class are given below : {:("Height (in cm)",157,152,153,154,155,156),("Number of students",7,4,3,5,9,7):} Find the median height.

Find the mean for the following data. {:("Marks obtained",10-20,20-30,30-40,40-50,50-60,60-70),("Number of students",8,6,12,5,2,7):}

Find the mean deviation from the mean for the following data: 5 2 9 10 12 15 8 6 2 2 2 6

Find the mean of the following set of numbers: 6,9,11,12 and 7

Find the mean, variance and standard deviation for the following data: 6,7,10,12,13,4,8,12