7.5 would be my best guess
        
                    
             
        
        
        
The probability that the reaction time for this density function is at most 2.5 seconds is equal to 0.9.
<h3>What is a density function?</h3>
A density function can be defined as a type of function which is used to represent the density of a continuous random variable that lies within a specific range.
<h3>How to calculate the probability that reaction time is at most 2.5 seconds?</h3>
P(X ≤ 2.5) = Fx(2.5)
Fx(2.5) = 3/2 - 3/2(2.5)
Fx(2.5) = 3/2 - 3/5
Fx(2.5) = 0.9.
Read more on density function here: brainly.com/question/14448717
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Complete Question:
The reaction time (in seconds) to a certain stimulus is a continuous random variable with pdf:
f(x) = 
What is the probability that reaction time is at most 2.5 seconds?
 
        
             
        
        
        
The answer is plus 4 because a positive plus a negative is a negative
        
             
        
        
        
The product of a number y and 12 or 12 times a number y. These are both equivalent expressions to 12y
 
        
             
        
        
        
Answer:
Jamie has 5 cards. his friend Bill gives him twice the number of cards he has. After this Jamie has 25 card total. I hope that this helps!!