CDF table for exponential distribution

Question

I know there is table for standard normal distribution CDF, but i can't find a CDF table for exponential distribution, i know i can transform exponential distribution to normal one by taking the log.

Answer 1

I know there is table for standard normal distribution CDF, but i can't find a CDF table for exponential distribution

Whether a table is necessary depends on the computational abilities of the era. At one time, a table of values of $\exp x$ would have been useful, but nowadays a button on your calculator handles that. So you get $1-\exp(-\lambda x)$ by first multiplying $\lambda$ and $x$, looking up $\exp(-\lambda x)$, and then subtracting from $1$. (There was a time when multiplication would be handled with $\lambda x=\exp(\ln\lambda+\ln\lambda x)$, using a table for both $\exp$ and $\ln$!)

i can transform exponential distribution to normal one by taking the log

If that were true, there'd be no point having a table for each distribution, since you can take the logarithm with a table or calculator. But actually, you can't make the transformation you describe. You can't connect $1-\exp(-\lambda x)$ to $\Phi(x):=\int_{-\infty}^x\frac{1}{\sqrt{2\pi}}\exp\frac{-t^2}{2}dt$ that neatly. Today, even your calculator probably doesn't have a button for $\Phi$, although you could grab a library function to do it if you were programming.