Alex, Bart, and Carl are brothers. Alex is the oldest and Carl is the youngest. The sum of the ages of the three brothers is 42. Alex's age is 3 more than twice Carl's age. The difference between Bart's and Carl's age is 7 years. Which system of equations could be used to determine the ages of all three brothers?

11. minitab software was used to find the lsrl for a study between x=age and y=days after arthroscopic shoulder surgery until an athlete could return to their sport. use the output to determine the prediction model and correlation between these two variables. predictor coef se coef t p constant -5.054 4.355 -1.16 0.279 age 0.2715 0.1427 1.9 0.094 r-sq = 31.16%

What would be the reasons for lines 3 and 4? a. addition property; subtraction property b. addition property; solve c. substitution property; subtraction property d. substitution property; prove

Each of the following data sets has a mean of x = 10. (i) 8 9 10 11 12 (ii) 7 9 10 11 13 (iii) 7 8 10 12 13 (a) without doing any computations, order the data sets according to increasing value of standard deviations. (i), (iii), (ii) (ii), (i), (iii) (iii), (i), (ii) (iii), (ii), (i) (i), (ii), (iii) (ii), (iii), (i) (b) why do you expect the difference in standard deviations between data sets (i) and (ii) to be greater than the difference in standard deviations between data sets (ii) and (iii)? hint: consider how much the data in the respective sets differ from the mean. the data change between data sets (i) and (ii) increased the squared difference îł(x - x)2 by more than data sets (ii) and (iii). the data change between data sets (ii) and (iii) increased the squared difference îł(x - x)2 by more than data sets (i) and (ii). the data change between data sets (i) and (ii) decreased the squared difference îł(x - x)2 by more than data sets (ii) and (iii). none of the above