SOLUTION: The time taken for a student to complete an exam is normally distributed with a mean of 40 minutes and a standard deviation of 5.5 minutes.
The probability a student takes betw
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The probability a student takes betw
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Question 1191285: The time taken for a student to complete an exam is normally distributed with a mean of 40 minutes and a standard deviation of 5.5 minutes.
The probability a student takes between k and 48 minutes is 0.4. What is the value of k? Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! z=(x-mean)/sd
z=(48-40)/5.5
=1.454
probability <48 minutes is 0.9271
use the table and find that for probability 0.5271 being less than a certain number of minutes, z=0.068
.
The probability that z is between 0.068 and 1.454 is 0.40
0.064=(k-40)/5.5
0.352=(x-40)
k=40.352 minutes
