Answer:
The standard error for the mean finish time of 30 randomly selected participants is 0.055 hours
Explanation:
Standard error = sample standard deviation ÷ sqrt (sample size)
sample standard deviation = 0.30 hours
sample size = 30
standard error = 0.30 ÷ sqrt(30) = 0.30 ÷ 5.477 = 0.055 hours