Select all the correct answers. Which two statements are true about a system? A system is a group of objects analyzed as one unit. Energy that moves across system boundaries is conserved. There’s only one way to define the boundaries of a system. All systems are made by humans.

1. there are 25 students who started computer programming in elementary school and 25 students who started computer programming in middle school. the first group had a mean final project grade of 95% and the second group had a mean final project grade of 92%. the line plot shows the differences after 10 rerandomizations. determine whether the difference in the means of the two groups is significant based on the line plot. explain your answer.

The graph below represents the number of dolphins in a dolphin sanctuary. select all the key features of this function.

Given the points a(-2, 1) and b(8, 6), find the coordinates of the point c on directed line segment ab, that partitions ab in the ration 2: 3.