The following are six years quarterly sales (in millions of dollars) of a manufacturer of heavy machinery:

Question:

The following are six years’ quarterly sales (in millions of dollars) of a manufacturer of heavy machinery: 83.8, 102.5, 121.0, 90.5, 106.6, 104.8, 114.7, 93.6, 98.9, 96.9, 122.6, 85.6, 103.2, 96.9, 118.0, 92.1, 100.5, 92.9, 125.6, 79.2, 110.8, 95.1, 125.6, and 86.7. At the 0.05 level of significance, is there a real cyclical pattern?