Question 910348
Re TY:
sd= {{{sqrt(p(1-p)n)}}} = {{{sqrt(.09*.91*500)}}} 0r = {{{sqrt(.91*45)}}} as 45 had been already determined.
p = .09,  m = {{{.09*500}}} = 45,  sd = {{{sqrt(.91*45)}}} = 6.4
45 ± 2•6.4 usual occurrences  23 to 58
would it be unusual to find 65 who cannot distinguish between the colors red and green? Yes