Answer:

And the explanation of this number is:"The number of text messages for Kendra it's 2.26 deviations above the mean"
Step-by-step explanation:
1) Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".  
2) Calculate the z score
Let X the random variable that represent the number of text messages per month, and for this case we know the distribution for X is given by:
 
  
Where  and
 and  
And the best way to solve this problem is using the normal standard distribution and the z score given by:
 
If we apply this formula to our probability we got this:

And the explanation of this number is:"The number of text messages for Kendra it's 2.26 deviations above the mean"
 
        
             
        
        
        
Answer: 6 = 6
Step-by-step explanation:
 
        
             
        
        
        
Answer:
A. 720 per hour
Step-by-step explanation:
1200+ <em>720</em> + 720 + <u>360</u> =3000
         <em>hr 1↑</em>+  hr 2↑ + <u>↑30 min</u>
 
        
             
        
        
        
Answer:
It is 1, 2, 3, or 4
Step-by-step explanation:
 
        
             
        
        
        
Answer:
it equals x=10 so i guess it's B
Step-by-step explanation: