Calculate the mean marks from the following data:
`{:("Marks",20-25,25-30,30-35,35-40,40-45,45-50,50-55),("No. of Students"," "10," "12," "8," "20," "11," "4," "5):}`

Calculate arithmetic mean from the following data by Short-cut Method: {:("Class Interval",20-25,25-30,30-35,35-40,40-45,45-50,50-55),("Frequency"," "10," "12," "8," "20," "11," "4," "5):}

Find out median marks from the following data : {:("Marks",0-10,10-20,20-30,30-40,40-50),("Number of Students"," "8," "30," "40," "12," "10):}

Caculate the median and mode from the following data : {:("Marks",0-10,10-20,20-30,30-40,40-50,50-60,60-70,70-80),("Number of Students"," "2," "18," "30," "45," "35," "20," "6," "3):}

Locate the median graphically from the following data : {:("Marks",0-10,10-20,20-30,30-40,40-50),("Number of Students"," "10," " 20," " 30," " 20," " 10):}

Calculate median of the following data : {:("Marks",46-50,41-45,36-40,31-35,36-30,21-25,16-20,11-15),("Number of Students"," "5," "11," "22," "35," " 26," "13," "10," "7):}

Calculate the median from the following series : {:("Age (Years)",55-60,50-55,45-50,40-45,35-40,30-35,25-30,20-25),("Number of Students"," " 7," "13," "10," "15," "30," "33," "28," "14):}

Obtain the mean , median and mode of the following data : {:("Marks",0-10,10-20,20-30,30-40,40-50,50-60,60-70,70-80),("Number of Students"," "5," "7," "15," "25," "20," "15," "8," "5):}

Calculate the mode from the following data : {:("Class Interval",20-24,25-29,30-34,35-39,40-44,45-49,50-54,55-59),("Frequency"," "3," "5," "10," " 20," "12," "6," "3," "1):}

Given the following data , find out median : {:("Age",20-25,25-30,30-35,35-40,40-45,45-50,50-55,55-60),("Number of Students"," "50," "70," "100," "180," "150," "120," "70," "60):}