An engineer claims that painting the exterior of a particular aircraft affects its cruising speed. To check this, the next 10 aircraft off the assembly line were flown to determine cruising speed prior to painting, and were then painted and reflown. The following data resulted.
Cruising Speed (knots)
|
Aircraft
|
Not Painted
|
Painted
|
|
1
|
426.1
|
416.7
|
|
2
|
418.4
|
403.2
|
|
3
|
424.4
|
420.1
|
|
4
|
438.5
|
431.0
|
|
5
|
440.6
|
432.6
|
|
6
|
421.8
|
404.2
|
|
7
|
412.2
|
398.3
|
|
8
|
409.8
|
405.4
|
|
9
|
427.5
|
422.8
|
|
10
|
441.2
|
444.8
|
Do the data uphold the engineer's claim?