Answer:
Step-by-step explanation:
-1, 3
 
        
                    
             
        
        
        
Given that,
Sample size= 83
Mean number= 39.04
Standard deviation= 11.51
We know the critical t-value for  95% confidence interval which is equal to 1.989.
We also know the formula for confidence interval,
CI=( mean number - critical t-value*standard deviation/(sample size)^(1/2), mean number + critical t-value*standard deviation/(sample size)^(1/2))
So, we have
CI= (39.04 - 1.989*11.51/83^(1/2), 39.04 + 1.989*11.51/83^(1/2)
CI= (39.04 - 2.513,39.04 + 2.513)
CI= (36.527,41.553)
Therefore, 95% confidence interval for these data is (36.527,41.553), and this result interpret that the true value for this survey sample lie in the interval (36.527,41.553).
 
        
                    
             
        
        
        
The answer and process is shown in the following picture
 
        
        
        
Answer:
2
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
200×20 = 4000 And 15×30 = 450
Step-by-step explanation:
Hope it helpz!!