What is the least common denominator of the equation 3/4(x-3)-1/2=2/3

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?

Look at the chart showing the results of a baseball player at bat. which is the probability of getting a hit?

The curved part of the figure is the semicircle what is the best approximation for the area of this figure