Solve this system using matrices:
x1 - x2 + x3 = 6
2x1 - x2 + x3 = 5
3x1 + x2 + 3x3 = -20

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 following frequency table relates the weekly sales of bicycles at a given store over a 42-week period.value01234567frequency367108521(a) in how many weeks were at least 2 bikes sold? (b) in how many weeks were at least 5 bikes sold? (c) in how many weeks were an even number of bikes sold?

At $1.32 million, they closed last month percent above what they paid in 2007." how much did they pay in 2007?