To find the mean, you add all of the numbers up and then divide by how many numbers there are. Mean is also known as the average. To find the medium, you have to list all the numbers in order then cross them out to find the middle. To find the mode, you find how many numbers are the same and count the number with the most repeats. Ex for mean.) 5 + 2 + 5 = 15. 15/3 because there are 3 numbers in the equation. 15/3 = 5. The mean is 5. Ex for median.) 1 2 2 3 4 5 7 9 9. 4 is in the middle so it is the median. Ex for mode) 34 35 34 34 32 7. There are more 34s than any other number so 34 is your mode.
The mean is the average. Add up all the numbers. Divide the sum by however many numbers there are. To find the median, list the numbers out from least to greatest. Take a number off the left, then a number of the right. Keep going until you have one number left in the middle. This is the median. If you have two numbers left, add them together and divide the sum by 2. The mode is the number that appears the most. If two or more numbers appear the same amount of times, they are all the mode. As for stem and leaf plots, you can Google them. They're really easy.
x is multiplied by two because we are looking for twice of x. 11 is added to the 2x because we are looking for eleven more than the sum of twice of x. Since 2x + 11 is less than 44, we use the lesser than ( < ) symbol.
