4. Fit a normal distribution to the data of Problem 22 in Review Practice Problems of Chapter 2 and test the null hypothesis at 5% level of significance that the data behave like a sample from a normal population. The data of Problem 22 is reproduced below. Find the observed level of significance.

Age [35-40) [40-45) [45-50) [50-55) [55-60) [60-65)

Frequency 60 75 68 72 90 55