Which situation is represented by the equation 6x = 4x + 18? a. James paid $18 for 4 books. What is the cost of one book? b. James paid the same amount for 6 books as he did for 4 books and a CD that costs $18. What was the cost of each book? c. Six times a number is the same as 4 times the number decreased by 18. What is the number, x? d. Six more than the number of red beads in a bag is the same as 18 more than 4 times the number of red beads in the bag. What is x, the number of red beads in the bag.

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