Answer:
0.392
Explanation:
Given :
Sample size, n = 144
Mean score, = 5.91
Standard deviation, σ = 2.4
The margin of error at 95% confidence, α = 0.05
The margin of error = Zcritical * σ/√n
We use Z because we σ is known
Zcritical at 95% = 1.96
The margin of error = 1.96 * 2.4/√144
The margin of error = 1.96 * 2.4/12
= 1.96 * 0.2
= 0.392