During a test, the scientist may try to prove or disprove just the null hypothesis or test both the null and the alternative hypothesis. If a hypothesis specifies a certain direction, it is called one-tailed hypothesis.
A mountain pass (also called a gap, saddle, or col) is a passage over a mountain range. They typically occur in valleys between mountain ridges, in low points along mountain watersheds or just the lowest point on a mountain ridge between two peaks. They can be relatively short in length (the width of a ridge) or they can be valleys many miles long. Mountain passes are often the location where roads and railways are built to get through the mountains. Many of them have become famous throughout history for their importance in trade and commerce.
The area east and south of the pass is home to the Tehachapi Pass Wind Farm, one of California's larger wind farms. The pass is also a proposed route for the California High-Speed Rail line between Palmdale and Bakersfield.The railroad landmark known as the Tehachapi Loop is about 18 miles (29 km) west of the summit.ehachapi Pass is a mountain pass crossing the Tehachapi Mountains in Kern County, California in the United States.