Answer:
11.218 - 11.812 feet
Step-by-step explanation:
The factory manager does not want to use the rods from the bottom 20% and the top 15%. In other words, the factory manager doesn't want percentile 0-20 and percentile 85-100.
To solve this question, you need to know the z score of percentile 20 and 85.
Z-score of percentile 20 is -0.94, then the calculation will be :
x= 11.5 feet+ 0.3 feet* z-score
x= 11.5 feet+ 0.3 feet* (-0.94)
x= 11.5 feet- 0.282 feet
x= 11.218 feet
Z-score of percentile 85 is +1.04 then the calculation will be :
x= 11.5 feet+ 0.3 feet* z-score
x= 11.5 feet+ 0.3 feet* 1.04
x= 11.5 feet+ 0.312 feet
x= 11.812 feet
The range for the rod will be 11.218 - 11.812 feet
