more than 75 , 85 , 95 , 105 , 115 , 125 , 135 , 145 / cf given / calculate Mean / assumed average

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

Income. Number of families

More than 75 150
More than 85 140
More than 95. 115
More than 105 95
More than 115 70
More than 125 60
More than 135 40
More than 145 25

Calculate mean ,