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# Time for action – confidence intervals

We create functions that will enable us to obtain confidence intervals of the desired size:

1. Create a function for obtaining the confidence intervals of the proportion from a binomial distribution with the following function:
```binom_CI = function(x, n, alpha)  {
phat = x/n
ll=phat-qnorm(alpha/2,lower.tail=FALSE)*sqrt(phat*(1-phat)/n)
ul=phat+qnorm(alpha/2,lower.tail=FALSE)*sqrt(phat*(1-phat)/n)
return(paste("The ", 100*(1-alpha),"% Confidence Interval for Binomial Proportion is (", round(ll,4),",", round(ul,4),")", sep=''))
}```
The arguments of the functions are `x`, `n`, and `alpha`. That is, the user of the function needs to specify the `x` number of success out of the `n` Bernoulli trials, and the significance level

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