#StatisticalAnalysis #Year11 #Advanced >[!info]- [Probability and data | NSW Curriculum Website](https://curriculum.nsw.edu.au/learning-areas/mathematics/mathematics-advanced-11-12-2024/content/n11/fa829162c5) >- MAV-11-09 solves problems involving probability in a variety of contexts >- MAV-11-10 displays and analyses datasets using summary statistics and graphical representations ## šŸ“– Prior Knowledge | Content | Prior knowledge | Used for | | ----------------- | --------------------------------------------------------------------------------- | -------------------- | | [[Probability A]] | - multistage events | - *repeated content* | | [[Probability B]] | - set notation<br>- conditional probability<br>- venn diagrams and two-way tables | - *repeated content* | ## Sets and set notation - Define a set as a collection of objects, called the elements of the set, and represent a set using notation such as $\{2,3,5,7\}$ and $\{0,2,4,6,\ldots\}$ - Use the notation $n(A)$ or $|A|$ to represent the number of elements in a finite set $A$ - Define the empty set as the set with no elements, denoted in set notation as $\emptyset$ - Use the notation $\overline{A}$, $A'$ or $A^c$ to represent the complement of a set $A$ with respect to some universal set $U$ - Define A to be a subset of B if all the elements of $A$ are elements of $B$ - Define the intersection $A\cap B$ of sets $A$ and $B$ to be the set of elements that are in $A$ and in $B$ - Define the union $A\cup B$ of sets $A$ and $B$ to be the set of elements that are in $A$ or in $B$ - Define sets A and B to be disjoint if $A\cap B=\emptyset$, that is, they have no elements in common - Use Venn diagrams in practical situations to represent and interpret sets that may intersect in various ways within a universal set - Establish and use the rule $|A\cup B|=|A|+|B|-|A\cap B|$ ## Probability - Define an experiment or a trial to be any procedure that can be infinitely repeated and has a well-defined set of possible outcomes known as the sample space, denoted $S$ - Identify an event $A$ as a subset $A$ of the sample space $S$ - Define the probability of each outcome to be $\frac{1}{|S|}$ when all the outcomes are equally likely and the probability of the event A to be $P(A)=\frac{|A|}{|S|}$ - Interpret the notation $\overline{A}$ to be the event 'A does not occur', interpret $A\cap B$ to be the event 'A and B both occur', and interpret $A\cup B$ to be the event '$A$ or $B$ occurs' - Use Venn diagrams to represent the relationship between events within the same sample space, including mutually exclusive events, that is, events that as subsets of the sample space are disjoint - Establish and use the rules $P(\overline{A})=1-P(A)$ and $P(A\cup B)=P(A)+P(B)-P(A\cap B)$ - Use arrays and tree diagrams to determine the outcomes and probabilities for multistage events ## Conditional probability - Define conditional probability as the probability that an event A occurs given that another event B has already occurred, and use the notation $P(A|B)$ - Examine conditional probability by restricting the sample space and event spaces in a Venn diagram, using a two-way table, a tree diagram and other arrays - Establish that $P(A|B)=\frac{|A\cap B|}{|B|}$ when all outcomes are equally likely by restricting the sample space and event space, and hence $P(A|B)=\frac{P(A\cap B)}{P(B)}$, provided $|B|\neq0$ - Use the formulas for $P(A|B)$ to solve practical problems involving conditional probability - Define two events to be independent if the occurrence of one event does not affect the probability that the other event occurs - Explain that two events A and B are independent means $P(A|B)=P(A)$ and $P(B|A)=P(B)$, and show algebraically that if one of these formulas is true, then the other is also true - Use the formula $P(A|B)=\frac{P(A\cap B)}{P(B)}$, and the test $P(A|B)=P(A)$ for independence to prove that if two events are independent, then $P(A\cap B)=P(A)\times P(B)$, and to prove conversely that if $P(A\cap B)=P(A)\times P(B)$, then A and B are independent - Solve practical problems involving independent events ## Data - Define a random variable as a variable whose value is the outcome of a random experiment - Compare discrete random variables with continuous random variables, describe their differences, and give practical examples of each - Organise finite datasets using a table or a spreadsheet, listing the values, frequency, relative frequency, cumulative frequency, and cumulative relative frequency - Graph the frequency, relative frequency, and cumulative frequency histograms and polygons of datasets, using spreadsheets or graphing applications, and identify the mode and median from the graphs, and from tables - Use the relative frequency to estimate the probability of results in experiments