Answer:
 
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
The test statistics is    
   
Step-by-step explanation:
From the question we are told that 
    The sample size is  n  =  100 
   The null hypothesis  is  
    The alternative hypothesis is  
    The sample mean is  
     The standard deviation is  
     The level of significance is  
Generally the test statistics is mathematically represented as 
         
=>      
=>       
     
 
        
             
        
        
        
Answer:
Look below
Step-by-step explanation:
Sigma (summation) and Pi (product) notation are used in mathematics to indicate repeated addition or multiplication

Hope this helps
 
        
             
        
        
        
Answer:
it will take 4 hours( I'm not so sure)
Step-by-step explanation:
$25x $15
------- = ------------- + 75
 1h. 1h
25x = 100
x =100/25
x = 4