Question 1127288: You were told that the amount of time lapsed between consecutive trades on a foreign stock exchange market 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 15 and 16 seconds?
Answer is 30% but not sure how to get it
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! You were told that the amount of time lapsed between consecutive trades on a foreign stock exchange market 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 15 and 16 seconds?
Answer is 30% but not sure how to get it
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Sketch all that data on a normal curve.
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Since the tail to the left of 13 is 7%,
find z = invNorm(0.07) = -1.476.
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Now solve for "s" using 13 = -1.476s + 15
Then s = 1.355
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Now find the area under the curve between x = 15 and x = 16
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Ans:: Area = normalcdf(15,16,15,1.355) = 0.2697 or 27%
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Cheers,
Stan H.
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