Answer:
46.75 minutes
Step-by-step explanation:
Mean time (μ) = 40 minutes
Standard deviation (σ) = 10 minutes
The third quartile is at the 75th percentile of a normal distribution. According to a z-score table, the corresponding z-score for the 75th percentile is z=0.675.
The z-score for any given time, 'X', is:
[tex]z=\frac{X- \mu}{\sigma}[/tex]
The third quartile for the time required to complete the form is:
[tex]0.675=\frac{X- 40}{10}\\X= 40+6.75=46.75\ minutes[/tex]
