The heights of a group of males have an approximate normal distribution with mean 1.73m and standard deviation 0.064m. Find the proportion of males who are:
a) between 1.7m and 1.9m tall
b) between 1.75m and 1.85m tall
c) taller than 2.010m
d) shorter than 1.8m
e) the height below which 90% of heights fall
f) the heights within which the middle 50% of heights fall
+37099 If you look at a Bell curve, the FIRST standard deviation covers 34% the second 14% the third 2%
A 1.7 to 1.9 is THREE standard deviations (1.7 + 3 (.064) = ~1.9) so
34+14+2 = 50 %
D 1.8 is ONE standard deviation above the mean for 34% all of the SHORTER than the mean covers another 50%
50% + 34% = 84%
See below: (ignore the 'same as others' 'less than others' etc) Just look at the numbers on the bottom
