Econometrics - confidence intervals

this is quite a common question in the exam papers,

it says obtain a 95% confidence intervals for B2 (Beta(subscript 2)).....

you are give the coefficient itself, R squared (the coefficient of determination) and the standard error. I was just wondering what the formula was to calculate this (its not one particular question im stuck on, just this type)

Thankyou in advance for any help

Hi,

So I take it you have ran a regression such as where is some unobservable error term, and obtained estimators for the coefficients(often called beta hat - , as well as the standard errors of the coefficents

The 95% confidence interval will be

Where is the t-stat value at the 2.5% level of significance for however many degrees of freedom in the regression. So if you had n=100 observations, and the model above with a constant and one explanatory variable you would have k=2, so you would need a t-stat of

Hi Robb,

Thats exactly what I meant, thankyou for explaining it (Clapping)

much appreciated