# One reason for the increase in the life span over the years has been the advances in medical technology.

One reason for the increase in the life span over the years has been the advances in medical technology. The average life span for American women from Email-trough 2007 is given by $$\displaystyle{W}{\left({t}\right)}={49.9}+{17.1}{\ln{{t}}}{\left({1}\leq{t}\right)}$$ where W(t) is measured in years and t is measured in 20-year intervals, with t=1 corresponding to the beginning of 1907.
a. Show that W is increasing on (1, 6).
b. What can you say about the concavity of the graph of W on the interval (1, 6)?

• Questions are typically answered in as fast as 30 minutes

### Plainmath recommends

• Get a detailed answer even on the hardest topics.
• Ask an expert for a step-by-step guidance to learn to do it yourself.

liingliing8
a) Calculating W'(t) we conclude that W is increasing on (1,6).
b) Calculating W"(t) we conclude that W is concave downward on (1,6).
w(t) is concave downwards in (1,6)