问题
单项选择题
Which statement best describes the properties of Student’s t-distribution（）
A. The t-distribution is symmetrical, defined by two parameters and is less peaked than the normal distribution.
B. The t-distribution is symmetrical, defined by a single parameter and is less peaked than the normal distribution.
C. The t-distribution is skewed, defined by a single parameter and is more peaked than the normal distribution.
答案
参考答案：B
解析：
The t-distribution is symmetrical like the normal distribution but unlike the normal distribution is defined by a single parameter known as the degrees of freedom and is less peaked than the normal distribution.