Question:
The survey is conducted to calculate average number of sickdays.The employees are categorised into nurses, doctors andadministrators. Stratified random sampling, is used with each groupforming a separate strata in order to conduct survey. The no. ofemployees in the strata are given in table below:
Table-1:
Number of employees in each category
| Doctors | Nurses | Administrators |
No. of employees | 120 | 80 | 10 |
Number of Sick days for 9 doctors, 7 nurses and 4administrators
Table-2:
Group | No of Sick Days | Mean | S² |
Drs | 8 | 7 | 10 | 12 | 19 | 6 | 13 | 12 | 9 | 10.67 | 15.5 |
Nurses | 4 | 8 | 3 | 12 | 7 | 10 | 15 | | | 8.43 | 18.29 |
Adm | 5 | 12 | 10 | 11 | | | | | | 9.5 | 9.67 |
a.Ă‚Â Ă‚Â Calculate the sample size from each strata ifproportional allocation is done for selecting total 25 employeesfrom table-1
b.Ă‚Â Ă‚Â Using the data from table-2 calculate the meannumber of sick days for that year.
c.Ă‚Â Ă‚Â Place a 95% confidence bound on the mean.
d. Calculate the total number of sick days for the year.
e.Ă‚Â Ă‚Â Place a bound on the total number of sick days andinterpret this bound.
