germany-abitur

2020 abitur__bayern_stochastik

9 maths questions

QA a 2 marks Combinations & Selection Combinatorial Probability View
An urn contains three green dice and two red dice. Two dice are randomly drawn from the urn in one draw. Give a term with which one can determine the probability that one red die and one green die are drawn.
QA b 3 marks Discrete Probability Distributions Probability Computation for Compound or Multi-Stage Random Experiments View
A green die and a red die are rolled simultaneously. The random variable $X$ describes the sum of the two numbers rolled. Give all values that the random variable $X$ can take and determine the probability $P ( X = 7 )$.
QB 1 5 marks Probability Definitions Probability Using Set/Event Algebra View
In a municipality there are 6250 households, of which 2250 have a fast internet connection. Two thirds of the households that have a fast internet connection also have a subscription to a streaming service. $46 \%$ of all households have neither a fast internet connection nor a subscription to a streaming service.
Consider the following events:\ $A$ : ``A randomly selected household has a fast internet connection.''\ $B$ : ``A randomly selected household has a subscription to a streaming service.''\ Create a completely filled four-field table for the described situation and check whether the events $A$ and $B$ are stochastically independent.
QB 2a 4 marks Binomial Distribution Compute Cumulative or Complement Binomial Probability View
Determine the probability for each case that among 10 contacted households
  • at least two do not yet have a fast internet connection.
  • exactly eight already have a fast internet connection.
QB 2b 2 marks Binomial Distribution MCQ Selecting a Binomial Probability Expression or Value View
Describe in the context of the problem an event whose probability is given by the term $0,2 ^ { 10 } + ( 1 - 0,2 ) ^ { 10 }$.
QB 2c 5 marks Binomial Distribution Find Minimum n for a Probability Threshold View
Determine how many households the company would need to contact at minimum so that with a probability of more than $99 \%$ at least one contacted household that does not yet have a fast internet connection would decide to set one up. Assume that every hundredth contacted household that does not yet have a fast internet connection decides to set one up.
QB 3a 2 marks Discrete Probability Distributions Proof of Distributional Properties or Symmetry View
Describe how one can immediately recognize that the expected value of $Y$ is equal to 2.
QB 3b 5 marks Discrete Probability Distributions Probability Distribution Table Completion and Expectation Calculation View
The variance of $Y$ is equal to $\frac { 11 } { 8 }$. Determine the values of $a$ and $b$.
QB 3c 2 marks Measures of Location and Spread View
The random variable $Z$, which for a fair coin describes the number of occurrences of ``heads'' in four rolls, also has the expected value 2 and analogously $P ( Z = 2 ) = \frac { 3 } { 8 }$. Calculate the variance of $Z$, compare it with the variance of $Y$, and based on this describe a qualitative difference in the probability distributions of $Z$ and $Y$.