The article “A Probabilistic Analysis of Dissolved Oxygen–

Biochemical Oxygen Demand Relationship in Streams”

(J. Water Resources Control Fed., 1969: 73–90) reports data on the rate of oxygenation in streams at 20°C in a certain region. The sample mean and standard deviation were computed as x
.173 and s
.066, respectively. Based on the accompanying frequency distribution, can it be concluded that oxygenation rate is a normally distributed variable? Use the chi-squared test with 
.05.