Let  be the random variable for the number of marks a given student receives on the exam.
 be the random variable for the number of marks a given student receives on the exam.
10% of students obtain more than 75 marks, so

where  follows a standard normal distribution. The critical value for an upper-tail probability of 10% is
 follows a standard normal distribution. The critical value for an upper-tail probability of 10% is

where  denotes the CDF of
 denotes the CDF of  , and
, and  denotes the inverse CDF. We have
 denotes the inverse CDF. We have

Similarly, because 20% of students obtain less than 40 marks, we have

so that

Then  are such that
 are such that


and we find

 
        
             
        
        
        
Answer:
Disagree
Step-by-step explanation:
Remember rotating 90 degrees  means (y,-x)
A= (1,2)
A'= (2,-1)
So it is disagreed.
Hope this help :)
 
        
                    
             
        
        
        
second answer to the left
 
        
             
        
        
        
You can break large numbers into a sum of a multiple(s) of 10 and the last digit of the number. For example, you can break 26 as 20+6, or 157 as 100+50+7.
Then, using the distributive property, you can turn the original multiplication into a sum of easier multiplications. For example, suppose we want to multiply 26 and 37. This is quite challenging to do in your mind, but you can break the numbers as we said above:

All these multiplications are rather easy, because they either involve multiples of 10 of single-digit numbers:
