If xi 's are the mid point of class intervals of grouped data, fi' s are the corresponding frequencies and x bar is the mean, then summation (fixi-xbar) is equal to

 

The Population of a town decreased by 12% during 1998 and then increased by 8% during 1999. Find the population of the town, at the beginning of 1998, if at the end of 1999 its population was 285120. Class 9 | Compound Interest

 

According to a census taken towards the end of the year 2009, the population of a rural town was found to be 64000. The census authority also found that the population of this particular town had a growth of 5% per annum. In how many year after 2009 did the population of this town reach 74088 ? Class 9 | Compound Interest

 

Mohit borrowed a certain sum at 5% per annum compound interest and cleared this loan by paying Rs. 12600 at the end of first year and Rs. 17640 at the end of second year. Find the sum borrowed. Class 9 | Compound interest

 

int dx/(secx + cosecx) Class 12 | Integral Calculus