# Why don’t we have standard T distribution like standard normal distribution

### Why would we use a t-distribution instead of the standard normal distribution?

The reason

**t**–**distribution is used**in inference**instead**of**normal is**due to the fact that the theoretical**distribution**of some estimators**is normal**(**Gaussian**) only when the**standard**deviation**is**known, and when it**is**unknown the theoretical**distribution is**Student**t**.**We**rarely know the**standard**deviation.### Why do we use the t-distribution instead of the standard normal distribution when calculating a confidence interval for a mean how does the t-distribution differ from the standard normal distribution?

The

**t**–**distribution**gives more probability to observations in the tails of the**distribution**than the**standard normal distribution**(a.k.a. the z-**distribution**).### How is the t-distribution similar to the standard normal distribution?

The T distribution is similar to the normal distribution,

**just with fatter tails**. Both assume a normally distributed population. T distributions have higher kurtosis than normal distributions. The probability of getting values very far from the mean is larger with a T distribution than a normal distribution.