Answer:
The upper 20% of the weighs are weights of at least X, which is  , in which
, in which  is the standard deviation of all weights and
 is the standard deviation of all weights and  is the mean.
 is the mean.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean  and standard deviation
 and standard deviation  , the z-score of a measure X is given by:
, the z-score of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Upper 20% of weights:
The upper 20% of the weighs are weighs of at least X, which is found when Z has a p-value of 0.8. So X when Z = 0.84. Then



The upper 20% of the weighs are weights of at least X, which is  , in which
, in which  is the standard deviation of all weights and
 is the standard deviation of all weights and  is the mean.
 is the mean.
 
        
             
        
        
        
3 and 1/2 can be rewritten as a fraction as 7/2.
7 can be written as 7/1.
When dividing by a fraction, simply multiply by the reciprocal.
7/2*1/7.
Then, cross multiply across the top.
7*1=7
2*7=14
So it's 7/14, which can be reduced to 1/2.
        
                    
             
        
        
        
Answer:
It would be the first one honey :)
Step-by-step explanation:
 
        
             
        
        
        
Answer:

Step-by-step explanation:
Step 1: Given equation: 
To get u, by subtraction equality property subtract both sides of the equation by   .
.
 
  
 
  
Step 2: By division equality property, divide both sides of the equation by t.

 
  
Therefore,  .
.
So, in Emily’s physics class, she got  .
.