Answer:
Highest area) Student's t-Distribution with 30 degrees of freedom
Middle) Student's t-Distribution with 50 degrees of freedom
Lowest are) Standard deviation distribution
Step-by-step explanation:
Knowing that higher area of the tails correspond to higher dispersion of the t- distribution, and the following properties of t-distribution:
- when the degrees of freedom increase , the dispersion diminishes
- when the degrees of freedom goes to ∞ , t- distribution approaches the standard normal distribution ( thus the z-curve is known as t-curve with df=∞ )
the correct answer is
Tail area : standard deviation < 50 df < 30 df