Following are 2017 and 2018 revenue data for Honeywell Internationals four segments. Use these data to forecast its 2019 revenue.

Honeywell International Segment Sales and Business-Unit Sales by Segment
$ millions	2018	2017
Aerospace sales
Commercial aviation original equipment	2266	1980
Commercial aviation aftermarket	4,298	4,082
Defense and space	3,732	3,242
Transportation systems	2,098	2,518
Total aerospace sales	$12,394	$11,822
Honeywell building technologies sales
Homes	$3,142	$3,586
Buildings	4,296	4,236
Total Honeywell building technologies sales	$7,438	$7,822
Performance materials and technologies sales
UOP Russle LLP	$2,276	$2,202
Process solutions	3,985	3,836
Advanced materials	2,278	2,233
Total performance materials and technologies sales	$8,539	$8,271
Safety and productivity solutions sales
Safety	$1,822	$1,735
Productivity solutions	3,247	2,776
Total safety and productivity solutions sales	$5,069	$4,511
Total consolidated sales	$33,440	$32,426

a. Calculate historic (year-on-year) sales growth for each business unit, segment, and total consolidated sales. Note: Round the percentage to two decimal places (for example, enter 14.56% for 14.55555%).

	Growth Rate
Aerospace sales
Commercial aviation original equipment	Answer
Commercial aviation aftermarket	Answer
Defense and space	Answer
Transportation systems	Answer
Total aerospace sales	Answer
Honeywell building technologies sales
Homes	Answer
Buildings	Answer
Total Honeywell building technologies sales	Answer
Performance materials and technologies sales
UOP Russle LLP	Answer
Process solutions	Answer
Advanced materials	Answer
Total performance materials and technologies sales	Answer
Safety and productivity solutions sales
Safety	Answer
Productivity solutions	Answer
Total safety and productivity solutions sales	Answer
Total consolidated sales	Answer

b. Use the historic growth in Total consolidated sales (from 2017 to 2018) calculated in Part a to estimate total consolidated sales for 2019. Note: Round your answer to the nearest whole dollar. Estimated total consolidated sales for 2019: c. Refine the sales forecast by using the sales growth rates for each of the four segments (from 2017 to 2018) calculated in part a to estimate 2019 sales for each segment. Determine a forecast for total consolidated sales for 2019. Note: Round your answer to the nearest whole dollar. Estimated total consolidated sales for 2019: d. Refine the sales forecast further by using the sales growth rates for each of the business units within each of the four segments. This means we use the separate historic growth for each line item in the table (calculated in part a) to estimate 2019 total consolidated sales. Note: Round your answer to the nearest whole dollar. Estimated total consolidated sales for 2019: e. Which approach do we believe is more accurate in forecasting total consolidated sales?