Statistics. By: Jerry Mear, Itzel Lazcano, Manuel Quiñonez, Nidya Díaz Sophomore Magnet Academy 2010. Measures of Central Tendency. The mean, median and mode are single central values that help describe a set number of data . Here there are some definitions and examples of terms.
By: Jerry Mear, Itzel Lazcano, Manuel Quiñonez, Nidya Díaz
Sophomore Magnet Academy
The mean, median and mode are single central values that help describe a set number of data .
Here there are some definitions and examples of terms
Data: 98 95 99 97 89 92 97 62 90
1. Organize the data
62 89 90 92 95 97 97 98 99
2. Find the mean
To find the mean find the sum of the values
62 +89+ 90 +92+ 95 +97+ 97+ 98+ 99= 819
Number of values 9
Divide by the number of values 819/9=91
3. Find the median
To find the median find the number that’s in the middle
62 89 90 92 95 97 97 98 99
This is the middle term
4. Find the mode
To find the mode: what number shows up the most?
97 because it occurs more that the other values
1, 20, 30, 40, 100
Find the median 30
The lower extreme –the smallest values of the set of numbers 1
The upper extreme – the largest number of the set of numbers 100
Finding the lower quartile and upper quartile
Lower quartile – the number between the median and the lower extreme
1, 20, 30 lower quartile = 20
Upper quartile –the number between the median and the upper extreme
30, 40, 100 upper quartile = 40
if there is more than one number between the median and the extreme take the mean of those values
After finding these make a box and whisker plot by
Marking the upper quartile, lower quartile, upper extreme, and lower extreme on a number line
Purpose: Stem and Leaf plots are used to organized sets of data.
Stem and Leaf Plot Tens Place Ones Place
The odds of an event happening, based on all the possible outcomes.
Find the probability of getting a prime number when you roll a
1. Find the number of favorable outcomes…
1,3,5, there are 3 favorable outcomes.
1,2,3,4,5,6 there are 6 total outcomes
2. Plug in the favorable outcomes and the total number of possible outcomes.
P(E) = ½
There is a 1 in 2, or 50% chance of getting a prime number.
The probability that a certain outcome will occur,
determined through experimentation.
Experimental Probability =
A coin is tossed 60 times. 27 times head appeared. Find the experimental probability of getting heads.
1. Find the total number of times heads appeared.
2. Find the total number of times it was tried.
#of experiments = 60
3. Plug the numbers into the formula.
27/60 = 9/20
Number of event occurrences
Total number of trials
We find the conditional probability by P(B|A)
Lets take this data 7 males say yes to an answer and 8 say no
P(did a chore | male ) = 7/15 because 7 out of 15 said they did a chore.