Exam 3 Definitions Flashcards

Flashcards for reviewing definitions for Exam 3, covering confidence intervals, mathematical models, relative frequency, central limit theorem, Z-score, standard error, margin of error, cumulative probability, normal curve properties, and confidence interval calculation.

What is a confidence interval?

A range of plausible values where we may find the true population parameter, typically the middle percentage of the total number of bootstraps.

What are mathematical models composed of?

Formulas and parameters that describe the shapes of populations.

What is relative frequency also known as?

P(x), the probability density function.

What are the two conditions that the Central Limit Theorem (CLT) satisfies?

A random sample and a sample that is large enough to take the shape of a bell.

What does a Z score (standardized value) measure?

The number of standard deviations that an observation is from the mean.

How is the Z score calculated?

z = (x - μ) / σ

In the equation x = μ + zσ, what does x equate to?

x = μ + zσ

What is standard error?

The standard deviation on a normal curve for sampling distributions.

What does the margin of error represent?

How far away observations are from their mean.

What is cumulative probability?

A percent and area to the left of a key x-value; interior probabilities, denoted as P(a ≤ x ≤ b) = P(x ≤ b) - P(x ≤ a).

How do you calculate the probability outside of the percentile?

By dividing it by the number of samples (p(x₁ ≤ x ≤ x₂)).

Is the normal curve symmetric or skewed?

Symmetric

What does σ determine on a normal curve?

Width

What percentages do 1, 2, and 3 standard deviations represent in a normal distribution?

68% = 1 SD, 95% = 2 SD, 100% = 3 SD

What is the Confidence Interval equation?

μ = (x̄ ± SE)