寿命(h) | 100~200 | 200~300 | 300~400 | 400~500 | 500~600 |
个数 | 20 | 30 | 80 | 40 | 30 |
寿命(h) | 频数 | 频率 |
100~200 | 20 | 0.10 |
200~300 | 30 | 0.15 |
300~400 | 80 | 0.40 |
400~500 | 40 | 0.20 |
500~600 | 30 | 0.15 |
合计 | 200 | 1 |
寿命(h) | 频数 | 频率 |
100~200 | 20 | 0.10 |
200~300 | 30 | 0.15 |
300~400 | 80 | 0.40 |
400~500 | 40 | 0.20 |
500~600 | 30 | 0.15 |
合计 | 200 | 1 |
A.20 | B.30 | C.40 | D.50 |
A.9.4,0.484 | B.9.4,0.016 |
C.9.5,0.04 | D.9.5,0.016 |
A.0.27,78 | B.0.27,83 |
C.2.7,78 | D.2.7,83 |
A.0.6小时 | B.0.9小时 |
C.1.0小时 | D.1.5小时 |
© 2017-2019 超级试练试题库,All Rights Reserved.