### Using HP 17bII+ for Cost Estimation with Linear Regression

 Johnson’s Chair Company has experienced the following costs for the first 6 months of the year: # Chairs Made5,0005,5004,8005,3004,9505,150 Total Costs\$120,000\$122,100\$118,540\$122,400\$119,100\$124,200

Entering data in HP 17bII+:

• [Shift] [CLR DATA]

• Press top soft key {SUM}

• 5,000 [INPUT]

• 5,500 [INPUT]

• 4,800 [INPUT]

• 5,300 [INPUT]

• 4,950 [INPUT]

• 5,150 [INPUT]

• [EXIT]

• Press top soft key {NAME}

• Press top soft key {ABCDE}{C}

• Press top soft key {FGHI}{H}

• Press top soft key {FGHI}{I}

• Press top soft key {RSTUV}{R}

• Press top soft key {RSTUV}{S}

• [INPUT]

• Press top soft key {GET}{*NEW}

• 120,000 [INPUT]

• 122,100 [INPUT]

• 118,540 [INPUT]

• 122,400 [INPUT]

• 119,100 [INPUT]

• 124,200 [INPUT]

• [EXIT]

• Press top soft key {NAME}

• Press top soft key {RSTUV}{T}

• Press top soft key {ABCDE}{C}

• [INPUT]

Johnson’s fixed cost:

• Press [SHIFT][MAIN]

• Press top soft key {SUM} {CALC} {MORE} {FRCST}

• Prompted ‘Select X Variable’

• Press top soft key {CHAIRS}

• Prompted ‘Select Y Variable’

• Press top soft key {TC}

• Displayed ‘LINEAR’

• Press top soft key {B} is Y intersect, this is fixed cost - when no chair was build.{M} is the unit cost

• Display 89,449.381 is the Answer

Johnsonï¿½s variable cost:

• Press top soft key {M}

• Display 6.178 which is the cost for one unit of chair.

How good is the fit of the linear regression line generated?

• Press top soft key {CORR} Display 0.716 this is the answer

Total costs for 5,400 chairs:

• Enter 5,400 then press {CHAIRS}

• Display 122,806.907 is the Answer.

Total costs were \$125,000, how many chairs:

• Enter 125,000 then press {TC}

• Display 5,755.023 is the Answer.

This solution is also applicable to HP 17bII and HP 19bII Financial Calculator.