Answer:
the probability is 0.0378
Explanation:
Given that;
cumulative distribution function: F (x ) = 1 - ( 1 / ( x + 1)³ )
probability the person's reaction time will be between 0.9 and 1.1 seconds will be;
p( 0.9 < x < 0.9 ) = F( 1.1 ) - F( 0.9 )
p( 0.9 < x < 0.9 ) = [1 - ( 1 / ( 1.1 + 1)³ )] - [1 - ( 1 / ( 0.9 + 1)³ )]
= [1 - ( 1 / ( 2.1)³ )] - [1 - ( 1 / ( 1.9)³ )]
= [1 - 0.107979] - [1 - 0.14579]
= 0.8920 - 0.8542
= 0.0378
Therefore, the probability is 0.0378