FTCE 5-9 Test Prep Center for Teaching and Learning

Competency 7 Notes Measures of Central Tendency Measures of central tendency are the three different ways of defining the center of a distribution: mean, median & mode. – The mode is the number that is repeated more often than any other number. – The median is the middle number, when the numbers arranged in order. – The mean is the average of the numbers.

Competency 7 Notes Correlation, Regression Correlation refers to the interdependence or co-relationship of variables. Regression is a way of describing how one variable, the outcome, is numerically related to predictor variables.

Competency 7 Notes Graphical Representations of Data A bar graph displays two or more relationships simultaneously. It is good for making comparisons.

Competency 7 Notes Graphical Representations of Data A Line graph is a graph that uses line segments to connect data points and shows changes in data over time.

Competency 7 Notes Graphical Representations of Data A pictograph is a graph that shows numerical information by using picture symbols or icons to represent data sets.

Competency 7 Notes Graphical Representations of Data A circle graph is a graph in the form of a circle that is divided into sectors, with each sector representing a part of a set of data.

Competency 7 Notes Probability: Dependent Event Events are dependent if the outcome of one event affects the outcome of another. – For example, if you draw two colored balls from a bag and the first ball is not replaced before you draw the second ball then the outcome of the second draw will be affected by the outcome of the first draw.

Competency 7 Notes Probability: Independent Event Events are independent if the outcome of one event does not affect the outcome of another. – For example, if you throw a die and a coin, the number on the die does not affect whether the result you get on the coin.

Competency 7 Notes Predicting Odds Odds are just an alternative way of expressing the likelihood of an event happening. – For example, the odds of catching the flu would be the expected number of flu patients divided by the expected number of non-flu patients.

Competency 7 Notes Sample Space A sample space is a complete list of all possible outcomes of a random experiment – For example, toss 2 coins. The sample space would be all combinations of those two coins: {(H,H), (H,T), (T,H) and (T,T)}

Competency 7 Notes Predictions: Experimental Probability Probability is the chance that some event will happen. One way to find the probability of an event is to conduct an experiment. – For example, take a marble from the bag. Record the color (blue) and return the marble. Repeat a few times. Count the number of times a blue marble was picked. The experimental probability the probability of getting a blue marble from the bag.

Competency 7 Notes Predictions: Theoretical Probability Probability is the chance that some event will happen. One way to find the probability of an event is to use a formula. – The formula for the probability of an event is:

Competency 7 Notes Counting Principle Counting Principle is used to find the number of possible outcomes when there are two or more characteristics. – For example, Sandra has three skirts and two tops. How many different outfits can she make with 1 skirt and 1 top?

Competency 7 Notes Addition Principle of Counting If the possibilities being counted can be divided into groups with no possibilities in common, then the total number of possibilities (outcomes) is the sum of the numbers of possibilities in each group. – For example, You want to buy a computer from one of two makes, Dell and Apple. Now, suppose also that those makes have 12 and 18 different models, respectively. Then how many models are there altogether to choose from? – Since we can choose one of 12 models of Dells or one of 18 of Apples, there are all together = 30 models to choose from.

Competency 7 Notes Multiplication Principle of Counting The multiplication counting principle states that there are m ways to order n things. This means that if one event can occur in m ways and another event can occur in n ways, then the number of ways that both events can occur together is mn. – For example, In the cafeteria you can choose either a turkey sandwich, a cheeseburger or a slice of pizza for your main meal. Then for dessert, you can have either grapes or cookies. By the multiplication counting principle we know there are a total of 3×2 ways to have your lunch and dessert.