To compute the mean, you simply have to sum all the elments in the data set and the divide the sum by the number of elements:
To compute the variance, we first need to compute the distance of each element from the mean. To do so, we build a "parallel" dataset, given by the difference of every value and the mean:
Now we need those difference squared:
The variance is the mean of this new vector, so
Finally, the standard deviation is simply the square root of the variance, so you have
The first battle in the Pacific between the empire of Japan against the US and its allies took place on December 8, 1941. The Japanese forces began their conquest on the pacific islands and it started its invasion of the Malaya. They were held by a resistance of British Indian fighter however it was not enough to hold off the overwhelming Japanese force.
Answer:
I have solved this problem on paper (Find pictures attached)
Answer:
30 red marbles
Step-by-step explanation:
If the ratio is 2 red marbles for every 5 blue marbles then you would add them together to find out how many marbles are in one group.
2+5=7
There are 7 marbles in each group.
Now we have to find out how many total groups there are by dividing the total amount of marbles by the amount in each group.
105÷7=15
There are 15 groups of 7 marbles.
Looking back at the ratio, we know that the 15 groups each have 2 red marbles and 5 blue marbles. So if there is 2 red marbles 15 times (2 marbles in 15 groups) we would multiply.
2×15=30
There are 30 red marbles.
I hope that makes sense.
