Answer:
6.5 minutes
Explanation:
We solve this question using this z-score formula.
z = (x-μ)/σ
where x is the raw score
μ is the population mean
σ is the population standard deviation
z = standard deviations above the mean = 0.43
x = 34 minutes
μ = 31.2 minutes
σ = unknown
n = 100
0.43 = (34 - 31.2)/ σ
0.43 = 2.8 / σ
Cross Multiply
0.43 × σ = 2.8
σ = 2.8/0.43
σ = 6.511627907
The standard deviation of the distribution is approximately 6.5 minutes
