Basic probability distributions - exclusive and compound events, binomial, Poisson, Gaussian distributions, normal distribution of error, standard error, principle of least squares, curve fitting, solution of linear equations - One Line Questions
1.
The sum of probabilities for all possible outcomes in any probability distribution must equal: —
1
2.
If P(A) = 0.5 and P(B) = 0.3, and A and B are independent events, what is P(A and B)? —
0.15
3.
The empirical rule (68-95-99.7 rule) for a normal distribution states that approximately what percentage of data falls within one standard deviation of the mean? —
68%
4.
What is the normal distribution of error? —
A distribution where errors are centered around zero and symmetric, with most errors being small and larger errors being less frequent.
5.
What is the shape of the Gaussian (Normal) distribution curve? —
A bell-shaped curve
6.
Which of the following is NOT a characteristic of a normal distribution? —
Asymptotic to the x-axis, but never touches it
7.
The Gaussian distribution is also known as the: —
Normal distribution
8.
Which distribution is often used to model rare events? —
Poisson distribution
9.
What is the primary application of the standard error? —
Estimating the uncertainty of a sample statistic as an estimate of a population parameter.
10.
In a Gaussian distribution, the mean, median, and mode are: —
Equal to each other.
11.
Curve fitting is essential for: —
Understanding the underlying relationship between variables and making predictions.
12.
What does 'compound events' refer to in probability? —
Events that can happen together or sequentially.
13.
Which type of function is most commonly fitted using the principle of least squares for simple experimental data? —
Linear function
14.
A smaller standard error indicates: —
Greater precision in estimating the population mean.
15.
What is the role of the parameter 'p' in a binomial distribution? —
It represents the probability of success in a single trial.
16.
If an event can occur in 'm' ways and another mutually exclusive event can occur in 'n' ways, in how many ways can either of these events occur? —
m + n
17.
For a standard normal distribution, what is the mean and standard deviation? —
Mean = 0, Standard Deviation = 1
18.
What are the mean and variance of a Poisson distribution? —
Mean = λ, Variance = λ
19.
The Poisson distribution is typically used to model the number of events occurring in a fixed interval of time or space, provided that these events occur with a known average rate and independently of the time since the last event. What parameter characterizes a Poisson distribution? —
λ (lambda, the average rate)
20.
What are the two parameters that define a Gaussian (Normal) distribution? —
μ (mean) and σ (standard deviation)
21.
What is the mean (expected value) of a binomial distribution? —
np
22.
What is the variance of a binomial distribution? —
np(1-p)
23.
If event A and event B are mutually exclusive, what is the probability of A or B occurring, P(A U B)? —
P(A) + P(B)
24.
For independent events A and B, what is the probability of both A and B occurring, P(A ∩ B)? —
P(A) * P(B)
25.
What is the formula for the probability mass function (PMF) of a Poisson distribution? —
P(X=k) = (λ^k * e^-λ) / k!
26.
What is the formula for the probability mass function (PMF) of a binomial distribution? —
P(X=k) = (n choose k) * p^k * (1-p)^(n-k)
27.
What is the formula for the probability density function (PDF) of a Gaussian (Normal) distribution? —
f(x) = (1 / (σ * sqrt(2π))) * e^(-(x-μ)² / (2σ²))
28.
Which probability distribution is used to model the number of successes in a fixed number of independent Bernoulli trials? —
Binomial distribution
29.
If a coin is flipped 10 times and lands heads 7 times, this scenario can be modeled by which distribution? —
Binomial distribution
30.
Which distribution is often used to approximate the binomial distribution when 'n' is large and 'p' is close to 0 or 1? —
Gaussian distribution
31.
The distribution that describes the sum of a large number of independent, identically distributed random variables, regardless of the original distribution, tends towards which distribution? —
Normal (Gaussian) distribution
32.
The standard error is most closely related to which statistical concept? —
Standard deviation of the sampling distribution of a statistic
33.
How is the standard error of the mean (SEM) typically calculated? —
Population standard deviation divided by the square root of the sample size.
34.
The principle of least squares is a method used in: —
Statistical analysis and data fitting.
35.
What is the 'standard error' of a statistic a measure of? —
The variability of the statistic across different samples.
36.
In the context of errors, what does the standard deviation of the normal distribution represent? —
The magnitude of the typical error.
37.
What does the parameter 'k' represent in the Poisson distribution PMF, P(X=k) = (λ^k * e^-λ) / k!? —
The number of events observed.
38.
What does the standard error represent in the context of statistical inference? —
The spread or variability of sample means around the population mean.
39.
In a binomial distribution, what does 'n' represent? —
The total number of trials.
40.
What is the standard error of estimate in the context of linear regression? —
A measure of the typical distance between the observed values and the regression line.
41.
When fitting a curve y = f(x) to data points (x_i, y_i) using least squares, the goal is to find the parameters of f(x) that minimize: —
The sum of the squared deviations: Σ(y_i - f(x_i))²
42.
For a linear regression model y = a + bx, what does the principle of least squares aim to find? —
The values of 'a' (intercept) and 'b' (slope) that minimize the sum of the squared differences between the observed y values and the predicted y values.
43.
In the context of solving linear equations, the principle of least squares is often used when: —
There are more equations than unknowns and the system is overdetermined, likely with measurement errors.
44.
What is the fundamental condition for two events to be mutually exclusive? —
They cannot occur simultaneously.
45.
In curve fitting using the principle of least squares, what does it mean to 'fit' a curve? —
To find a curve that best represents the trend of the data by minimizing the sum of the squares of the vertical deviations between observed and predicted values.
46.
What is the primary goal of the principle of least squares? —
To minimize the sum of squared errors.
47.
Under what conditions can a binomial distribution be approximated by a Poisson distribution? —
When n is large and p is small, such that np is a finite constant.
48.
When are two events considered independent? —
When the occurrence of one event does not influence the probability of the other.
49.
If you have a set of data points (x_i, y_i) and you are fitting a linear model y = mx + c, the least squares method minimizes the sum: —
Σ(y_i - (mx_i + c))²