Which expressions is equivalent to the on below?
9^x
a.3*3^x
b.3*3^2x
c.3^2x
d.(3*3)^x
e.3^x*3^x
f.3^2*3^x

You were told that the amount of time lapsed between consecutive trades on the new york stock exchange followed a normal distribution with a mean of 15 seconds. you were also told that the probability that the time lapsed between two consecutive trades to fall between 16 to 17 seconds was 13%. the probability that the time lapsed between two consecutive trades would fall below 13 seconds was 7%. what is the probability that the time lapsed between two consecutive trades will be between 14 and 15 seconds?