A Grade of 4

Difficulty: Hard · Topics: Probability, Statistics, T-Scores

The table shows the maths report grades of the students in a class.

Grade 1 2 3 4 5 --- --- --- --- --- --- Students 1 3 3 1 2

What is the T-score of a student with grade 4?

(Use the standard deviation s=√(Σ (x i-bar x)^2)/(n-1).)

(A T-score is T=50+10z, where z=(x-bar x)/(s) is the z-score.)