The graph below shows $f^{\prime\prime}$. Use it to answer the following questions.

1. Over what interval(s) is $f$ concave up?

   Hint (a):

   $f$ is concave up when $f^{\prime\prime}$ is positive. Where is the given graph positive?

2. Estimate $f^{\prime\prime\prime}(5)$.

   Hint (b):

   This is asking for the slope of the given graph at $x = 5$.

3. At what $x$-value(s) does $f$ have a point of inflection?

   Hint (c):

   This is where $f^{\prime\prime}$ changes sign. Where does the given graph change from negative to positive and vice versa?

4. At what $x$-value(s) does $f^\prime$ have a minimum value?

   Hint (d):

   f ′ has a minimum where its slope changes from negative to positive.
   The slope of $f^\prime$ is $f^{\prime\prime}$. So where does $f^{\prime\prime}$ change from negative to positive?