In a data set is estimated that the range is 36.?

a) With nothing known about the population, except its range, the most conservative estimate comes from putting 1/2 the samples to the far left and the other 1/2 to the far right. This gives st. dev. = 18.

remaining two done as by Cidyah.

a)

Range ≈ 6 S.D

S.D ≈ (1/6) range = (1/6)(36) = 6

b)

Sample size = ( z sd / e) ^2

z = 1.96 for 95% confidence interval

Sample size = ( (1.96)(6) / 3)^2 = 15.36

n = 16

c)

Sample size = ( (1.96)(6) / 2)^2 = 34.6

n = 35