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).
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
5a + s = 2662
a + s = 1198
4a = 1464
a = 366
5(366) + s = 2,662
1830 adult tickets sold
2662 - 1830 = 832
832 student tickets sold
If you mean how do you get x by it's you divide both sides by 8, to cancel out the multiplication between x and 8, meaning that it would end up being x=7, sorry if that didn't answer your question correctly.
Answer:
The area formulas for a triangle and a parallelogram require multiplying base by height.
A rectangle and parallelogram with the same base and height will have the same area.