Simple Regression
a) RCB manufacturers black & white television sets for overseas markets. Annual exports in thousands of units are tabulated below for the past 6 years. Given the long term decline in exports, forecast the expected number of units to be exported next year.
|Year |Exports |Year |Exports |
|1 |33 |4 |26 |
|2 |32 |5 |27 |
|3 |29 |6 |24 |
b) A small hospital is planning for future needs in its maternity wing. The data below show the number of births in each of the past eight years.
|Year |Births |Year |Births |
|1 |565 |5 |615 |
|2 |590 |6 |611 |
|3 |583 |7 |610 |
|4 |597 |8 |623 |
Use simple linear regression to forecast the annual number of births for each of the next three years. Determine the coefficient of determination for the data and interpret its meaning.
Moving Averages
IPC’s Plant estimates weekly demand for its many materials held in inventory. One such part, the CTR 5922, is being studied. The most recent 12 weeks of demand for the CTR 5922 are :
|Week |Demand in units |Week |Demand in units |
|1 |169 |7