Create a Python function calculating the confidence interval for the mean value if you know - the sample size (n); - the mean value of the sample (mean); - standard deviation (sig); - level of confidence (conf). In your answer, specify the length of the resulting confidence interval (the difference between the right and left ends), rounded to integers.

`from math import sqrt def conf_interval(n, mean, sig, conf): z_value = abs(conf - mean) sq_n = sqrt(n) interval = z_value / sq_n return interval conf_interval(3, 1, 2, 1)`