a lathe is set to cut bars of steel into lengths of 6 centimeters. the lathe is considered to be in perfect adjustment if the average length of the bars it cuts is 6 centimeters. a sample of 121 bars is selected randomly and measured. it is determined that the average length of the bars in the sample is 6.08 centimeters. the population standard deviation is 0.44 centimeters.

In an ecosystem, marsh snails feed on phytoplankton and painted turtles feed on marsh snails. pollution has resulted in the depletion of phytoplankton. what effect would this situation likely have on the population of marsh snails and painted turtles? as phytoplankton were destroyed, the population of marsh snails would most likely then the population of painted turtles would mostly likely a. 1. increase 2. decrease 3. stay the same b. 1. increase 2. decrease 3. stay the same

These three organisms are interdependent on each other for their survival. what will happen if foxes are eliminated from the region? a. there will be more rabbits and less grass in the region. b. there will be more grass and fewer rabbits in the region. c. there will be fewer rabbits and less grass in the region. d. there will be more rabbits and more grass in the region.

Spider crabs live in the shallow regions of the ocean floor. algae tend to grow on the surface of spider crabs. the algae provide the crabs protection from predators by camouflaging them. the spider crabs give the algae shelter. what does this description suggest? 1. the algae are parasites of the spider crabs. 2. the algae and the spider crabs have a mutualistic relationship. 3. the spider crabs are commensals, and the algae are parasites. 4. the spider crabs benefit from the algae living on them. 5. the spider crabs are parasites of the algae.