Consider the endothermic reactions in Exercise 250. Let A denote the event that a reaction's final temperature is 271 K or less. Let B denote the event that the heat absorbed is above target. Determine the following probabilities.
Step 1 of 5:
The summarized data regarding 204 endothermic reactions is given
Final temperature conditions 
Heat absorbed (cal) 

Below target 
Above target 

266 K 
12 
40 
271 K 
44 
16 
274 K 
56 
36 
Also, it is given that A denote the event the reaction’s final temperature is 271 K or less and B denotes the event that the heat absorbed is above target.
Using this, we need to find the required values.
Step 2 of 5:
(a)
Here we have to find the value of P(AB).
AB denotes the event that the temperature of the reaction is 271 K or less and the heat of the reaction is above target.
The outcomes favouring this event are 40+16 and total number of outcomes is 12+44+56+40+16+36=204.
So the value of P(AB) becomes
P(AB)=
=
=0.2745
Thus, P(AB)=0.2745.
Step 3 of 5:
(b)
Here we have to find the value of P(AB).
AB denotes the event that the final temperature of the reaction is 271 K or less or the heat is above target.
The outcomes favouring this event are 12+44+40+16+36 and the total number of outcomes is 204.
So, the value of P(AB) become
P(AB)=
=
=0.7255
Thus, P(AB)=0.7255.