Answer:
The score is 
Step-by-step explanation:
From the question we are told that
The population mean is 
The standard deviation is 
From the question we are told that the score follow a normal distribution
i.e 
The proportion of score in the top 10% is mathematically

Where x is the minimum score required to be in the top 10%
Now the 
So

So

So the critical value of 0.10 from the normal distribution table is 
So


X = $ 52 for the 12 books Diego bought
Answer:
true
Step-by-step explanation:
The answer is umu( M + m )