Podcast
Questions and Answers
Which of the following is NOT a characteristic of a normal distribution?
Which of the following is NOT a characteristic of a normal distribution?
- Bell-shaped curve
- Symmetrical distribution
- Mean, median, and mode are all equal
- Has a range of negative infinity to positive infinity (correct)
A student measures the height of all the trees in a park. Which type of random variable is the height of a tree?
A student measures the height of all the trees in a park. Which type of random variable is the height of a tree?
- Discrete random variable
- Normal random variable
- Continuous random variable (correct)
- Standard normal random variable
Which of the following statements about a standard score is TRUE?
Which of the following statements about a standard score is TRUE?
- It is always a positive value.
- It represents the number of standard deviations a value is away from the mean. (correct)
- It is only used for normal distributions.
- It is always less than 1.
What is the relationship between the mean and standard deviation of a normal distribution?
What is the relationship between the mean and standard deviation of a normal distribution?
Which of the following is an example of a discrete random variable?
Which of the following is an example of a discrete random variable?
Flashcards
Random Variable
Random Variable
A set of numbers assigned to outcomes of an experiment.
Normal Distribution
Normal Distribution
The distribution of a continuous random variable, bell-shaped.
Standard Score
Standard Score
Indicates how many standard deviations a value is from the mean.
Discrete Random Variable
Discrete Random Variable
Signup and view all the flashcards
Continuous Random Variable
Continuous Random Variable
Signup and view all the flashcards
Study Notes
Random Variables
- A random variable assigns numerical values to experiment outcomes.
- A continuous random variable's distribution can be bell-shaped (normal distribution).
- A discrete random variable's values often result from counting.
- A continuous random variable's values often result from measurements.
Normal Distribution
- A normal distribution's graph is bell-shaped.
- A standard normal distribution has a mean of 0 and standard deviation of 1.
- A normal curve is a bell-shaped curve.
Standard Score
- A standard score indicates how many standard deviations a value is from the mean.
Measures of Central Tendency
- The mean measures the central location of a random variable.
Empirical Rule
- The Empirical Rule (68-95-99.7% rule) describes the proportion of data within certain standard deviations of the mean in a normal distribution.
Examples of Random Variables
- Time spent on social media by a high school student is a continuous random variable.
- Employee salary is a continuous random variable.
- Calories in a sandwich are a discrete random variable.
- Number of children in a family is a discrete random variable.
- Number of tails when tossing a coin twice is a discrete random variable.
Variance
- Variance can be calculated by averaging the squared deviations from the mean, weighted by their probabilities.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
