‎Which of following statements isare true about the t-distribution with k degrees of freedom‎1 the t-distribution is symmetric 对称‎ 2the t-distribution with k degrees of freedom has a smaller standard

D. (1) only.

The t-distribution is not always symmetric, but it approaches symmetry as the degrees of freedom increase. Therefore, statement (1) is true.

Statement (2) is false. As the degrees of freedom increase, the t-distribution approaches the standard normal distribution, which has a standard deviation of 1. Therefore, the t-distribution with k degrees of freedom has a larger standard deviation than the t-distribution with k+1 degrees of freedom.

Statement (3) is also false. The t-distribution has a smaller variance than the standard normal distribution when the degrees of freedom are greater than 1