Answer:
475.
Step-by-step explanation:
We have been given that for a normal distribution with μ=500 and σ=100. We are asked to find the minimum score that is necessary to be in the top 60% of the distribution.
We will use z-score formula and normal distribution table to solve our given problem.

Top 60% means greater than 40%.
Let us find z-score corresponding to normal score to 40% or 0.40.
Using normal distribution table, we got a z-score of  .
.
Upon substituting our given values in z-score formula, we will get:





Therefore, the minimum score necessary to be in the top 60% of the distribution is 475.
 
        
             
        
        
        
We know that
<span>1. The number of all 4-letter words written using the alphabet of 20 symbols (from A to T) is 
20</span><span>^4=160,000
</span><span>
 2. The number of all 4-letter words written using the alphabet of 19 symbols (from B to T) is 
19</span><span>^4=130,321
</span><span>
 3. The difference represents exactly the number of all words of the inhabitants of the island of Jumble
difference=</span>(160,000-130,321)= 29679.
the answer is
29679
        
             
        
        
        
Answer:
D) 3.28
Step-by-step explanation:
820/x=100/2.5
(820/x)*x=(100/2.5)*x       - we multiply both sides of the equation by x
820=40*x       - we divide both sides of the equation by (40) to get x
820/40=x
20.5=x
x=20.5
now we have:
2.5% of 820=20.5
 
        
             
        
        
        
Answer:
3 roots
Step-by-step explanation:
(9x+7)(4x+1)(3x+4)=0 
x=-7/9 or - 1/4 or - 4/3
 
        
             
        
        
        
Answer:
25 feet my guy and u deserve a meme scroll down for it
Step-by-step explanation: