# Questions tagged [exponential-distribution]

A distribution describing the time between events in a Poisson process; a continuous analogue of the geometric distribution.

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### Calculate mean and quartiles for exponential distribution, which consists of a sum of two E-functions [closed]

How to calculate the mean, quartiles and variance for an exponential distribution with the following function: 17/99 e^(-0.5y) + 82/99 e^(-0,25y)
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### Why doesn't R use Inverse Transform Sampling to sample from the Exponential Distribution?

I was reading this question about the algorithm that R uses to sample from the Exponential($\lambda$) distribution. It looks like R uses the Ahrens-Dieter algorithm to sample from the exponential ...
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### Question about how to interpret certain data (am I correct in using the exponential distribution)?

Let's say my data has certain parameters $x_{1},...,x_{n}$ and there are two events, let them be $h_{1},h_{2}$. I'm considering interpreting the data via an exponential distribution because in this ...
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### Why do simulated arrival times from a Poisson distribution seem to show periodicity?

I am experimenting with simulated arrival times drawn from a Poisson distribution. To construct the arrival times, I am randomly drawing inter-arrival times from the inverse CDF, which is ...
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### modeling time between calls with exponential distribution

I've read that time between calls (in a call center) can be modeled with exponential distribution. My question is this: the shape of the exponential distribution has a decreasing nature. Suppose that ...
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### Calculating the exponential growth rate against the standard deviation of the year coefficient

I have time-series abundance data for various locations. I would like to calculate the exponential growth rate for each location against the standard deviation of the year coefficient. My dataframe ...
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### DataCamp exercise about distributions

I was studying some statistics in DataCamp and they assigned me this exercise that I can't solve. I tried speaking with people that know more statistics than me and we can't seem to agree in an answer....
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### Difference between Power law distribution and Exponential distribution?

What is the difference between Power law distribution and Exponential distribution? They both look similar! 29 views

### Is log-rank parametric or non-parametric test, and why?

How is the log-rank test a "non-parametric test" according to wikipedia.org if one has to specify the parametric survival model for this test? We may run log-rank under the assumption of ...
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### Statistical Inference Casella & Berger Exercise 7.11 [duplicate]

I'm self studying statistics using Casella & Berger Statistical Inference and I'm confused about a detail in solution to exercise 7.11. Here's the problem I'm try to solve: Let $X_1, ..., X_n$ be ...
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### How are sums and differences of independent Exponential random variables distributed?

If we are given X1, X2, X3, X4 , all exponential random variables with the same mean λ and said that another random variable T = X1 + X2 + X3 - X4. Can we then say T basically has a Gamma ...
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### Biasness of an estimator depends on whether you take expectation of the estimator or its inverse

(Please read until the end) know Consider two ways of writing the exponential distribution- (A) $\frac{1}{\beta} e^{-\frac{x}{\beta}}$ and (B) $\theta e^{-x\theta}$ If I estimate $\beta$ or $\theta$...
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### Write the PDF of an exponential prior given E[$\theta$] = 2

I am reviewing old exercise solutions and the following info is given: Assume that the conjugate prior for θ (as a special case of the gamma distribution) is following the exponential distribution ...
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### Find pdf of X+Y [duplicate]

Let X ∼ Exp(λ) and Y ∼ Exp(μ) be two independent exponential random variables, where λ, μ > 0. Find the probability density function of X + Y if λ ̸= μ. I have successfully find ans if λ = μ, but ...
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### What are the operational links between exponential and weibull distribution

I recently read a very interesting article about competing risks that came with simulations. In these, the author defines a Weibull distributed variable w using an ...
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### Sum of exponential decays with normally distributed lifetimes

If I have the sum $$f(t)=\frac{1}{N}\sum_{i=1}^N e^{-\frac{t}{\tau_i}}$$ where each $\tau_i$ is distributed normally with mean $\tau$, what will be the mean functional form of $f(t)$ in the large $N$ ...
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### Exponential Posteriori with a Uniform Prior

I'm studyng for a final exam and found this problem from another generation, but I don't know how I should continue... I will be gratefull for any help, thanks you. Let be $X|\theta\sim U(0,\theta)$ ...
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### How to use the exponential distribution to generate samples from the chi-square and beta distributions?

I am supposed to use rexp() in R to draw from an exponential distribution with mean 1, and then use those draws to generate 1000 draws from each of the following: ...
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We have an estimator $\hat{\theta}\geq 0$ for $\theta$, with distribution function $P\{\hat{\theta}\leq t \}=1-e^{-t/\theta}$, which we can recognize as the cdf of the exponential distribution. Our ...