Here is how I completed the problem:
I started by creating a ratio:

<em>Where 'x' is the desired amount of the 18% solution of sulfuric acid. 
</em>From here, I solved for 'x':
<em>
</em>







∴You will need to add 1080ml of 18% Sulfuric Acid in order to obtain a 15% solution.
 
        
        
        
Answer:
No, a convenience sample was taken.Therefore, the sample may not be representative of all college students in terms of number of hours studied per week.
Step-by-step explanation:
One of the important conditions required in other to estimate the mean of the population from the confidence interval. Requires that the data must be a random Sample. This is to ensure that sample values are not biased and as such are representative of the larger group of data.
However, in the scenario described above, the sample chose. Are friend's of the student, this makes the data lack randomness as those who aren't friends to the student do not stand a chance of being selected. The sampling procedure employed is called convenience sampling. 
 
        
             
        
        
        
Answer: It should be 18...(Multiple of 9)
Step-by-step explanation:
 
        
             
        
        
        
Answer:
Of means multiply in math (most of the time).  
So multiply.  
2/5 x 7/10 = 14/50 divided by 2/2 = 7/25 
Step-by-step explanation: