In the last lecture, we saw the following output between parking duration and building area

Estimate of coefficient of building area is 0.03 approx and its standard error or standard deviation is 0.007 approx.   We can assume that the coefficient follows normal distribution with mean of 0.03 and standard deviation of 0.007.  Thus, we can find 95% confidence interval by adding and subtracting twice standard deviation from the mean value.

Mean + twice standard deviation = 0.03 + 2*0.007 = 0.044

Mean - twice standard deviation = 0.03 - 2*0.007 = 0.016

Hence, the confidence interval is (0.016, 0.044)