Answer:
First graph
Step-by-step explanation:
see the attached figure to better understand the problem
Let
x -----> the temperature in degrees Fahrenheit
we know that
The chef allow a hamburger cooked to a temperature in the interval
[160,170]
so
All real numbers greater than or equal to 160 degrees Fahrenheit and less than or equal to 170 degrees Fahrenheit
therefore
<u><em>Verify each graph</em></u>
<em>First graph</em>
Include temperatures under 160 degrees or over 170 degrees
therefore
This graph represents the conditions under which the chef will not allow the hamburger to be served
<em>Second graph</em>
This graph include the temperatures of 160 degrees or 170 degrees
therefore
This graph represents conditions under which the chef will allow the hamburger to be served
<em>Third graph</em>
This graph represent the interval [160,170]
therefore
This graph represents conditions under which the chef will allow the hamburger to be served
<em>Fourth graph</em>
This graph represent the interval (160,170)
therefore
This graph represents conditions under which the chef will allow the hamburger to be served