How to find the values of k?

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Can someone please explain to me how to do question 5a? Thanks!

1 Answer
David B.
Jan 24, 2018

#k=1/ln(9)#

Explanation:

The trick to answering this question is to remember that the area under the probability density function for all allowed values of the variable must be #1#. Therefore:

#int_1^9 k/x dx = 1#

#k [ln(x)]_1^9 = 1#

#k*[ln(9)-ln(1)] = 1#

#k=1/ln(9)#

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