4. The reflecting dish of a parabolic microphone has a cross-section in the shape of a parabola. The microphone itself is placed on the focus of the parabola. If the parabola is 24 inches wide
and 9 inches deep, how far from the vertex should the microphone be placed?

1. 6 inches
2. 8 inches
3. 16 inches
4. 4 inches

Can someone answer this question? : )

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

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?