MA681 Project 1 Sept 2017 Center Pivot Irrigation Systems are throughout the world and in about half the sprinkler irrigation systems in the U.S. Even if you haven't seen one up close, you have probably seen them from the air due to the distinctive visual pattern they create. In simple terms, the system consists of a large arm, like the one pictured above, comprised of spans and towers. The arm is connected to a pivot point which provides power, water, and chemicals. The towers have powered wheels that propel the arm slowly around the pivot as water and chemicals are applied to the crops at controlled rates. Power required for each tower is about 1HP. In the U.S., the large rotating arm is typically 1320 feet long (1/4 of a mile (440 yards) to the outer wheels. As shown in the picture above, there is usually an end-gun that extends about 100 feet beyond the outer wheels. Typical full rotation around the pivot takes slightly less than a day. Center pivot systems are operated with a minimum amount of supervision, monitored with just a few simple statistics. One statistic is the rotation speed of the system. Although the speed is not directly observed, full rotation time for the system provides a way to calculate average rotation speed. The file rot35.txt contains the rotation times for an irrigation system. Calculate a 90% confidence interval for the speed of the rotating arm at the outer wheels. 21.80086 23.74087 24.6675 22.1376 21.4186 23.80423 23.11184 24.23174 24.826 21.44181 22.09314 22.96205 22.27362 23.23669 22.05037 21.8075 22.5501 24.55148 23.21969 24.36872 24.56083 23.8828 21.84536 21.90287 21.55993 22.91966 22.74965 24.86386 21.56766 24.81992 22.77892 21.23745 22.1006 21.12459 21.0579321.80086 23.74087 24.6675 22.1376 21.4186 23.80423 23.11184 24.23174 24.826 21.44181 22.09314 22.96205 22.27362 23.23669 22.05037 21.8075 22.5501 24.55148 23.21969 24.36872 24.56083 23.8828 21.84536 21.90287 21.55993 22.91966 22.74965 24.86386 21.56766 24.81992 22.77892 21.23745 22.1006 21.12459 21.05793