The numbers of beads on 500 handcrafted bead necklaces follow a normal distribution whose mean is 24 beads and standard deviation is 4 beads.
so....
About 24 necklaces have more than 28 beads.
About 48 necklaces have more than 28 beads.
About 80 necklaces have more than 28 beads.
About 96 necklaces have more than 28 beads
About 80 necklaces have more than 28 beads.
Z score is 28-24/4=1
(1-.8413)=0.1587
500*0.1587=79.35~80
i did this like 2 or 3 years ago .
