c) 0.975
d) t-distribution
c) A standard normal distribution
b) Population must be normal
c) t-distribution
b) Decreases
d) A normal distribution
b) Symmetric and bell-shaped
c) 𝑛 − 1
d) 𝜎/𝑛
c) 𝜇
b) The probability distribution of a sample statistic
c) Symmetric for low degrees of freedom
b) It is symmetric and bell-shaped
c) 𝜒 2 -distribution
d) t-statistic
b) 24
c)
c) 30
a) Standard error