Darryl has written 60 percent, or 12 pages, of his history report. Darryl wants to figure out how many total pages he needs to write. Darryl’s work is shown below. Step 1: Write 60 percent as a ratio. StartFraction part Over whole EndFraction = StartFraction 60 Over 100 EndFraction

Step 2: Write an equivalent ratio using the number of pages done so far. StartFraction 60 Over 100 EndFraction = StartFraction 12 Over question mark EndFraction

Step 3: Divide the part by 5 to get 12.

Step 4: Divide the whole by 12 to get the total number of pages.

What mistake did Darryl make?
In Step 1, Darryl should have written the ratio as 100 Over 60 .
In Step 2, Darryl should have put 12 in the denominator.
In Step 3, Darryl should have divided the part by 12.
In Step 4, Darryl should have divided the whole by 5.

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