C. 6
Exploration: i got it right.
        
             
        
        
        
Answer:
x+.8x=27
1.8x=27
x=15
4/5(15)=12
So 15 and 12
Step-by-step explanation:
 
        
             
        
        
        
Answer:
    
  
When we compare the significance level 
 we see that 
 so we can reject the null hypothesis at 10% of significance. So the  the true mean is difference from 21 at this significance level.
Step-by-step explanation:
Data given and notation  
 represent the sample mean
 represent the population standard deviation 
 sample size  
 represent the value that we want to test
 represent the significance level for the hypothesis test.  
z would represent the statistic (variable of interest)  
 represent the p value for the test (variable of interest)  
State the null and alternative hypotheses.  
We need to conduct a hypothesis in order to check if the average age of the evening students is significantly different from 21, the system of hypothesis would be:  
Null hypothesis:
  
Alternative hypothesis:
  
The statistic is given by:
  (1)  
Calculate the statistic
We can replace in formula (1) the info given like this:  
    
P-value
Since is a two sided test the p value would be:  
  
Conclusion  
When we compare the significance level 
 we see that 
 so we can reject the null hypothesis at 10% of significance. So the  the true mean is difference from 21 at this significance level.
 
        
             
        
        
        
Because of the fact that the amberjack is essentially three snappers, it can be shown as 3s
since one snapper is one s, and the amberjack is 3s, we can combine like terms
s+3s = 4s
because altogether, the fish weigh 44 pounds, 4s would equal 44 (shown as 4s = 44), from there, simply divide by 4 on both sides to get the weight of a snapper;
s = 11
Small bonus (finding an amberjack)
Since an amberjack is equal to three snappers, and a snapper is 11 pounds, an amberjack would be 33 pounds.