The average score of the student in the class at a 99% confidence lies between 1.252 and 3.028
Explanation:
Given values are
n = 14  = 2.14   σ = 1.29  z value for 99% confidence = 2.576
The mean is known one
= (z σ/√14)
=  (2.576 ×1.29÷√14)
[tex](2.576 ×1.29÷√14)[/tex]
= 2.576 × 0.345
= 0.888
 =  mean- 0.888 = 2.14  - 0.888 = 1.252
 =  mean+0.888 =  2.14 + 0.888 = 3.028
The average score of the students in the class at a 99% confidence lies between 1.252 and 3.028
