I was reading this article (https://www.scirp.org/pdf/ojs_2021101415023495.pdf) here and came across the following equations (page 7):
- Coverage Probability of a Binomial Random Variable:
$$Cp(p,n) = \sum_{k=0}^{n} I(k,n) \binom{n}{k} p^k (1-p)^{n-k}$$
- Expected Length of the Interval:
$$EL(p,n) = \sum_{k=0}^{n} \binom{n}{k} p^k (1-p)^{n-k} [ U(x) - L(x)]$$
I am interested in learning how I can derive these two formulas.
For instance, suppose if I start with some Random Variable "x" that has a Binomial Probability Distribution Function (https://en.wikipedia.org/wiki/Binomial_distribution). I understand that :
The "Coverage Probability" (https://en.wikipedia.org/wiki/Coverage_probability) refers to probability of the Confidence Interval containing the parameter of interest
And the "Expected Length" (https://stats.stackexchange.com/questions/18379/expectation-of-length-of-a-confidence-interval, Estimate length of confidence interval) refers to the length of the Confidence Interval relative to the Variance
But how can I use this probability distribution function to derive these two formulas starting from the Binomial Probability Distribution Function?
Thanks!