In 9 years a father wants to accumulate $50,000 to pay for his daughters college expense . If he can get 7% interest , compound quarterly , how much must he invest now to achieve his goal ?

For the equations below which statement is true ?

The parabola opens: y=√x-4 (principal square root) up down right left

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?