Reading 4: Common Probability Distributions
50 questions available
Key Points
- Discrete random variables have countable outcomes.
- Continuous random variables have infinite possible outcomes within a range.
- The probability of a specific value in a continuous distribution is zero.
- A cumulative distribution function (cdf) F(x) gives the probability that X is less than or equal to x.
Key Points
- Uniform distribution probabilities are constant across the range of outcomes.
- Binomial distribution applies to independent trials with two outcomes (success/failure).
- Expected value of a binomial variable is n * p.
- Variance of a binomial variable is n * p * (1 - p).
Key Points
- Normal distribution is symmetric around the mean.
- Standard normal distribution: Mean = 0, Standard Deviation = 1.
- 90 percent confidence interval: Mean +/- 1.65 standard deviations.
- 95 percent confidence interval: Mean +/- 1.96 standard deviations.
- Linear combinations of normal variables are also normal.
Key Points
- Lognormal distribution is bounded by zero and skewed to the right.
- Student's t-distribution has fatter tails than the normal, defined by degrees of freedom (n-1).
- Chi-square and F-distributions are bounded by zero and used in hypothesis testing.
- Monte Carlo simulation generates distributions of outcomes based on random inputs.
Questions
Which of the following best describes a discrete random variable?
View answer and explanationFor a continuous uniform distribution defined between a lower limit a and an upper limit b, what is the probability that the random variable X takes on a value greater than b?
View answer and explanationIn a binomial distribution with n trials and probability of success p, what is the expected number of successes?
View answer and explanationWhich of the following is a key property of the normal distribution?
View answer and explanationA portfolio manager wants to determine the probability that a portfolio's return will fall below a minimum acceptable level. Which measure should be maximized to minimize this probability?
View answer and explanationHow is a z-value calculated for a random variable X from a normal population?
View answer and explanationFor a lognormal distribution, which of the following statements is true regarding the possible values of the random variable?
View answer and explanationWhat is the 95 percent confidence interval for a standard normal random variable?
View answer and explanationIf an investor has a holding period return of 20 percent over one year, what is the continuously compounded annual rate of return?
View answer and explanationThe Student's t-distribution approaches the standard normal distribution as:
View answer and explanationWhich of the following parameters is necessary to completely describe a multivariate normal distribution for the returns of n assets?
View answer and explanationA chi-square distribution is bounded from below by:
View answer and explanationMonte Carlo simulation is best described as a technique that:
View answer and explanationIf the probability of success in a single trial is 0.40, what is the probability of exactly 2 successes in 5 independent trials (Binomial distribution)?
View answer and explanationWhat is the probability that a continuous uniform random variable defined between 2 and 10 takes on a value of exactly 5?
View answer and explanationAn analyst estimates the mean return of a stock to be 10 percent with a standard deviation of 20 percent. If returns are normally distributed, the 90 percent confidence interval for the return is:
View answer and explanationWhich of the following is a property of the standard normal distribution?
View answer and explanationShortfall risk is best defined as:
View answer and explanationIf an asset's price today is 100 and it increases to 110 over one year, what is the continuously compounded annual return?
View answer and explanationCompared to the normal distribution, the Student's t-distribution has:
View answer and explanationThe F-distribution is defined by:
View answer and explanationIf a cumulative distribution function F(x) represents the probability that X is less than or equal to x, how is the probability that X lies between a and b calculated?
View answer and explanationWhich distribution is typically used to test the equality of variances of two normal populations?
View answer and explanationA stock has an expected return of 12 percent and a standard deviation of 15 percent. If the threshold return is 2 percent, what is the Safety-First Ratio?
View answer and explanationIn a continuous uniform distribution ranging from 0 to 20, what is the probability that the random variable falls between 5 and 15?
View answer and explanationWhat is the variance of a binomial random variable with n=10 trials and probability of success p=0.5?
View answer and explanationWhen using Roy's Safety-First Criterion to choose among portfolios, which portfolio is preferred?
View answer and explanationWhich of the following is a characteristic of the lognormal distribution?
View answer and explanationFor a standard normal distribution, what is the probability that a value lies to the left of 0?
View answer and explanationIf the continuously compounded annual rate of return is 10 percent, what is the holding period return after 2 years?
View answer and explanationWhat is a limitation of Monte Carlo simulation?
View answer and explanationWhich distribution describes the sum of squared values of n independent standard normal random variables?
View answer and explanationIn a binomial experiment with 1 trial, the distribution is called a:
View answer and explanationFor a normal distribution with mean 50 and standard deviation 5, what is the z-score of an observation of 60?
View answer and explanationIf a cumulative distribution function F(x) = 0.60, what does this indicate?
View answer and explanationWith 10 degrees of freedom, the t-distribution is:
View answer and explanationWhich of the following is true regarding a linear combination of normally distributed random variables?
View answer and explanationIf a stock's price is modeled using a lognormal distribution, what can be said about the stock's returns?
View answer and explanationFor a discrete uniform distribution with n possible outcomes, what is the probability of each outcome?
View answer and explanationRoy's Safety-First Criterion states that the optimal portfolio maximizes:
View answer and explanationWhat is the approximate probability that a normally distributed random variable falls within one standard deviation of the mean?
View answer and explanationWhen constructing confidence intervals for small samples from populations with unknown variance, which distribution is most appropriate?
View answer and explanationWhich of the following is true about the F-distribution?
View answer and explanationIf a cumulative distribution function F(x) = x/10 for x in {1, 2, 3, 4}, what is F(3)?
View answer and explanationWhat is the critical z-value for a 95 percent confidence interval?
View answer and explanationIn a simulation of stock option values, the process of generating random values for risk factors based on assumed distributions is a key step in:
View answer and explanationIf two events are independent, the probability of both occurring is determined by:
View answer and explanationWhich distribution uses the parameter 'degrees of freedom' equal to n - 1?
View answer and explanationWhat is the lower bound of a normal distribution?
View answer and explanationA key difference between a univariate and a multivariate normal distribution is:
View answer and explanation