In tucson, arizona, the air pollution index averages 62.5 during the year with a standard deviation of 18. assuming normality, the index falls within what interval 95% of the time?

a) (8.5, 116.5)
b) (44.5, 80.5)
c) (45.4, 79.6)
d) (26.5, 98.5)
e) not enough info given

over the argument its not good to fight.

hello from mrbilldoesmath!

answer:

the domain is the set { -2, 0, 2, 3}

discussion:

the domain is the set of x values in the ordered pairs (x,y). taking the x, or first component, of each ordered pair gives   -2, 0, 2, 3.

you,

mrb