Question 1091259
the 10% percentile is at z=-1.28
the 90th percentile is at z=+1.28
multiply that by the sd and add to mean to get 90% cut off and subtract to get 10% cut off
574*1.28=734.7, round to 735
(2634, 4104) units are gm.
the mean greater than 3400 is 
z>(3400-3369)/574/sqrt (25)
z>155/574
z>0.2700
That probability is 0.3936.