Answer:x<-7
Step-by-step explanation:
3x -15x - 30 > 54
-12x-30>54
-12x<54+30    
I moved 30 from left side to right which becomes positive and > becomes <
-12x<84
-12x/-12<84/-12           I used my calculator to do this 
x<-7
 
        
             
        
        
        
Answer:
the first one
Step-by-step explanation:
the answer is the first one
 
        
             
        
        
        
Answer:
3,000 or 2,000 depends of where it starts at zero or 1,000
Step-by-step explanation:
 
        
             
        
        
        
Answer:
 
  
And rounded up we have that n=421
Step-by-step explanation:
We know that the sample proportion have the following distribution:

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 90% of confidence, our significance level would be given by  and
 and  . And the critical value would be given by:
. And the critical value would be given by:
 
The margin of error for the proportion interval is given by this formula:  
 (a)
    (a)  
And on this case we have that  and we are interested in order to find the value of n, if we solve n from equation (a) we got:
 and we are interested in order to find the value of n, if we solve n from equation (a) we got:  
 (b)
   (b)  
We assume that a prior estimation for p would be  since we don't have any other info provided. And replacing into equation (b) the values from part a we got:
 since we don't have any other info provided. And replacing into equation (b) the values from part a we got:
 
  
And rounded up we have that n=421