Answer:
0.42 Â & 0.55
Step-by-step explanation:
Mean length = Â 0.42 + 0.53+ 0.55 + 0.48 + 0.51/5
           =  0.498
0.42 -  0.498  =  - 0.078‬  Â
0.53 -  0.498  =   0.032‬
0.55 -  0.498  =   0.052‬
0.48 - 0.498  =   - 0.018‬
0.51  - 0.498  =    0.012‬
The nails to be thrown out are:
0.42 Â & 0.55 because their deviations from the mean are not within 0.05 inch