Costs for standard veterinary services at a local animal hospital follow a normal distribution with a mean of $88 and a standard deviation of $24. what is the probability that one bill for veterinary services costs between $42 and $133?

 the probability that one bill for veterinary services costs between $42 and $133 will be given as follows
P(42<x<133) 
z=(x-μ)/σ
where:
μ-mean
σ-standard deviation
thus
when x=42:
z=(42-88)/24=-1.92
thus
P(x<42)=0.0281

when x=133
x=(133-88)/24=1.875
thus
P(x<133)=0.9699
Thus
P(42<x<133) 
=0.9699-0.0281
=0.9418

0.9418

Logical equivalent of the give question is its contrapositive

Where are the functions?