Maggie wants to know how many students in her school enjoy watching sports on TV. She asks all 25 students in her math class and finds that 60% of her classmates enjoy watching sports on TV. She claims that 60% of the school's student population would be expected to enjoy watching sports on TV. Is
Maggie making a valid inference about her population?

O Yes, it is a valid inference because she asked all 25 students in her math class

O Yes, it is a valid inference because her classmates make up random sample of the students in the school

O No. it is not a valid inference because her classmates do not make up a random sample of the students in the school

O No, it is not a valid inference because she asked all 25 students in her math class instead of taking a sample from her geography class

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