Do you have a picture would probably make more sense if you added one
        
             
        
        
        
Answer:
a
  
b
 
Step-by-step explanation:
From the question we are told that 
 The mean value is 
 The standard deviation is  
Considering question a 
The sample size is  n = 9 
Generally the standard error of the mean is mathematically represented as 
       
=>    
 
=>  
Generally the probability that the sample mean hardness for a random sample of 9 pins is at least 51 is mathematically represented as 
       

      
=>   
From the z table  the area under the normal curve to the left corresponding to  2.5  is 
     
=> 
=> 
Considering question b 
The sample size is  n = 40
    Generally the standard error of the mean is mathematically represented as 
       
=>    
 
=>  
Generally the (approximate) probability that the sample mean hardness for a random sample of 40 pins is at least 51 is mathematically represented as  
        
=> 
=>  
From the z table  the area under the normal curve to the left corresponding to  5.2715 and 
=>  
So
    
=> 
 
        
             
        
        
        
Answer: she bought 5 bouquets 
explanation:  add the yellow and white daisies together to get 18 then do 
90 ÷18=5
 
        
             
        
        
        
<span>denominator is </span>number below the line in a common fraction.
Here's picture to show what is a denominator: