Answer:
The travel time that separates the top 2.5% of the travel times from the rest is of 91.76 seconds.
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Mean of 80 seconds and a standard deviation of 6 seconds.
This means that 
What travel time separates the top 2.5% of the travel times from the rest?
This is the 100 - 2.5 = 97.5th percentile, which is X when Z has a p-value of 0.975, so X when Z = 1.96.




The travel time that separates the top 2.5% of the travel times from the rest is of 91.76 seconds.
5) 74.925
6) 470
i think this is correct but i'm not completely sure
So 8x5=40 and 10×4=40 so you and your friend meet at the 40 th min
Let Cameron be x years old now.
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<u>Now:</u>
Cameron = x
Uncle =3x
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<u>4 years ago:</u>
Cameron = x - 4
Uncle = 3x - 4
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<u>4 years ago, Uncle is 4 times older:</u>
3x - 4 = 4(x - 4)
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<u>Find x:</u>
3x - 4 = 4(x - 4)
3x - 4 = 4x - 16
4x - 3x = 16 - 4
x = 12
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<u>Find the age:</u>
Cameron = x = 12
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Answer: Cameron is 12 years old now.