what is the probability that a randomly selected monthly cell phone bill is more than $100?

Question

average monthly household cellular phone bill is $73, with a standard deviation of $11.35

Answer 1

averaej =73$ & standard deviate=11.35

100-73=27$/11.35=2.4 times standard d (sigma)

theory av "random" variashun sae 68% R inside 1 standard d av averaej

95% inside 2 sigma

99.6% inside 3 sigma

2.4 sigma=bout 98%, so chans yer bill>=100 is bout 2%