Answer is A. 20.25
cause 20.25 x 9 = 81
√81 = 9
so 9 is the geometric mean <span>between 4 and 20.25</span>
        
             
        
        
        
Answer: 29/139
Explanation:
Total student: 139 (66 boys/73 girls)
Football: 56 student (28 boy/28 girl)
Tennis: 54 student (27 boy/ 27 girl)
Running: 29 student (18 girls/11 boys)
The probability that a student chose running is 29/139
        
             
        
        
        
The answer is 6hours in 122 minutes do umknow
        
             
        
        
        
Answer:
The minimum level for which the battery pack will be classified as highly sought-after class is 2.42 hours
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean  and standard deviation
 and standard deviation  , the zscore of a measure X is given by:
, the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

What is the minimum level for which the battery pack will be classified as highly sought-after class
At least the 100-10 = 90th percentile, which is the value of X when Z has a pvalue of 0.9. So it is X when Z = 1.28.




The minimum level for which the battery pack will be classified as highly sought-after class is 2.42 hours
 
        
             
        
        
        
I thing the answer is 7 days