Answer:
The reason why standard deviation of the entire class is greater than standard deviation of males and females considered separately, is that mean values for males and females are different from each other.
Step-by-step explanation:
The concept of mean is well represented by the following formula
mean =  , where x1, x2, xn are the observations and N is the number of observations (population).
, where x1, x2, xn are the observations and N is the number of observations (population).
Standard deviation represents the distance between each observation and the mean of the population (all observations). The formula for this parameter is:
Standard deviation =√[((x1 - x)² + (x2-x)² + ....+ (xn-x)²)/N-1], where x1, x2,..., xn are the observations and x is the mean value.
In this case you have that each height registered is an observation and the number of observations represents the N value. As you can see if the mean for males is different from that of females their standard deviation will be different too. Usually males have heigths greater than that of females (1.77 vs 1.64, in USA for example), and heights inside each group will be more similar than between groups. Then, when you mix all observation there will be an increase in standard deviation, because you are mixing very different heigths
 
        
             
        
        
        
Answer:
1=x or x=1 
Step-by-step explanation:
3(x+2)-10=4x-6+x
distribute 
3x+6-10=4x-6+x
combine like terms
3x-4=5x-6
subtract 3x from each side 
-4=2x-6
add 6 to both sides 
2=2x
divide by 2
1=x or x=1 
 
        
                    
             
        
        
        
<u>Answer:</u>
x ---> 1
y ---> 5
<u>Step-by-step explanation:</u>
We are given paired values for two variables x and y and we are to determine the constant number by which each term is increased such that they are in a proportional relationship.
For x, we have the following paired values:

So here the difference between each consecutive term is 1 so the constant is 1.
And for y, we have:

In this case, the difference between each consecutive term is 5 so the constant is 5.
 
        
             
        
        
        
1. You have that:
 - The<span> lengths of the bases are (6x-1) units and 3 units.
 - The midsegment has a length of (5x-3) units.
 2. To solve this exercise, you must apply the formula for calculate the length of the midsegment of a trapezoid, which is shown below:
 Midsegment=Base1+Base2/2
 As you can see, the midsegment is half the sum of the bases of the trapezoid.
 3. When you substitute the values, you obtain:
 (5x-3)=[(6x-1)+3]/2
 4. Now, you can solve the problem by clearing the "x":
</span>
 (5x-3)=[(6x-1)+3]/2
 2(5x-3)=6x-1+3
 10x-6=6x+2
 10x-6x=2+6
 4x=8
 x=8/4
 x=2