Suppose an environmental change affects the organism in Exercise 49 in such a way that an individual is only half as likely as before to survive to age x years. If the number of female births f(x) remains the same, how is the ideal age for reproduction affected by this change?

Data from Exercises 49

Suppose that for a particular semelparous organism, the likelihood of an individual surviving to age x years is p(x) = e^−0.2x and that the number of female births to an individual at age x is f(x) = 5x^0.9. What is the ideal age for reproduction for an individual organism of this species?