Question

Following is grouped data for duration of fixed deposits of 100 senior citizens from a central bank:
Calculate the limits of fixed deposits of central 50% senior citizens.​

Answer 1

Answer:

301.2 - 598.8  Days

Step-by-step explanation:

Day              Mean Days         f            f*mean     f(x- Mean)²

0-180              90                     15         1350          15*360²

180-360         270                    20        5400         20*180²

360-540        450                    25        11250         0

540-720        630                    30        18900       30*180²

720-900        810                     10         8100          10*360²

                             Total           100        45000     150*180²

Mean = 45000/100 = 450

Standard Deviation = √150*180²/100   = 180√1.5 = 220.45

z between -0.675  & 0.675  for Central 50 % data

z = (x - Mean)/SD

-0.675 = (x - 450)/220.45

=> x - 450 = -148.8

=> x = 301.2

0.675 = (x - 450)/220.45

=> x - 450 = 148.8

=> x = 598.8

Limits of Fixed seposit of central 50% data  = 301.2 - 598.8  Days