Nationwide, the amount charged by the doctors for performing a particular minor surgical procedure averages $1220 and varies with a standard deviation of $300. We randomly select 160 bills from the population of all bills charged for this surgery. Let represent the average amount charged for these 160 surgical procedures.
The probability that the average amount charged over these 160 procedures is more than $1180 is
A. 0.046.
B. 0.448.
C. 0.552.
D. 0.954.